Pitting, grooving and edge corrosion, class by class
Three defects that are gauged differently and judged differently. This table keeps them apart: what intensity or extent triggers action, how the reading is taken, what remaining thickness is accepted, and — for every society — where the rule book says nothing. Every cell carries its clause and its PDF page.
- table
- T04
- last verified
- 2026-08-04
- verified by
- —
- cycle
- each UR Z10 revision, and each January
Pitting — the trigger, the reading, and the accepted remaining thickness
Two different pitting rules are in circulation and they are not interchangeable. The side-structure rule works on intensity and a percentage of the as-built thickness. The other-structures rule works on a formula against the renewal thickness. Which one applies depends on where the pitting is, not on how bad it looks. 20 rows · every value carries its clause and PDF page
| Document · scope | Intensity that triggers actionand what the percentage is measured on | How the reading is takencleaning, gauging, which figure is recorded | Side structures — accepted remaining thicknessbulk carrier side frames and attached plating | Other structures — accepted remaining thicknessthe formula against t_ren |
|---|---|---|---|---|
| IACS UR Z10.2 Rev.37Single side skin bulk carriers — §8 applies to CSR ships only | 15 % intensity in an area where coating is required by CSR; the 15 % is based on pitting or grooving on one side of a plate only. Figure 1 prints 5, 10, 15, 20 and 25 % scattered — PDF p. 9 §8.2.1 · PDF p. 42 | strip a patch at least 300 mm across, at the worst-pitted spot on the plate, down to bare metal; gauge the five deepest pits inside that patch; the thinnest of the five readings is the one booked Annex V adds the tool: a 10 mm transducer will not suffice, so a 3 to 5 mm miniature transducer or a pit gauge is required — PDF p. 124 §8.2.1 · PDF p. 42 | the frame webs, the end bracket webs and their flanges keep 75 % of as-built; the side shell, hopper tank and topside tank plating each side frame lands on keeps 70 % of as-built, in a band reaching up to 30 mm out on either side of the frame both figures are floors on what survives inside a pit, a groove or any other locally wasted patch, and t_ren caps them from above §8.2.1 · PDF p. 42 | t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two applies to plates with pitting intensity less than 20 %. A second test runs alongside it: average the plating over any one cross section and that average must still make the CSR general-corrosion renewal thickness — §8.2.2, PDF p. 43 §8.2.2 · PDF p. 42 |
| IACS UR Z10.5 Rev.20Double side skin bulk carriers — §8 applies to CSR ships only | 15 % intensity in an area where coating is required by CSR; the 15 % is based on pitting or grooving on one side of a plate only. Figure 1, PDF p. 9 §8.2.1 · PDF p. 41 | strip a patch at least 300 mm across, at the worst-pitted spot on the plate, down to bare metal; gauge the five deepest pits inside that patch; the thinnest of the five readings is the one booked §8.2.1 · PDF p. 41 | the side shell, hopper tank and topside tank plating each side frame lands on keeps 70 % of as-built, in a band reaching up to 30 mm out on either side of the frame without being greater than t_ren. The 75 % frame-web figure of Z10.2 is not printed here — a double side skin bulk carrier has no cargo hold side frames §8.2.1 · PDF p. 41 | t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two applies to plates with pitting intensity less than 20 %. A second test runs alongside it: average the plating over any one cross section and that average must still make the CSR Chapter 13 renewal thickness — PDF p. 42 §8.2.2 · PDF p. 41 |
| IACS UR Z10.4 Rev.18Double hull oil tankers — §8 applies to CSR ships only | 20 % intensity is the ceiling of the criterion, not a gauging trigger the individual-measurement criterion is written for plates with pitting intensity less than 20 %; the UR prints no 15 % trigger because it carries no side-structure clause §8.2.1 · PDF p. 35 | not published the section carries no cleaning-to-bare-metal step and no five-deepest-pits step; those sit in the bulk carrier URs §8.2 · PDF p. 35 | not published the side-structure clause of Z10.2 §8.2.1 and Z10.5 §8.2.1 has no counterpart in the tanker UR §8.2 · PDF p. 35 | t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two a second test runs alongside it: average the plating over any one cross section and that average must still make the CSR general-corrosion renewal thickness — §8.2.2, PDF p. 35 §8.2.1 · PDF p. 35 |
| IACS UR Z10.1 Rev.25Oil tankers, ore/oil ships — no CSR section | 20 % intensity — a reporting trigger, not an acceptance criterion the remark bites on bottom plating. At 20 % intensity or above, and either wasted into the substantial corrosion band or pitted to an average depth of one third of the actual plate thickness or worse, the plating goes on the record in the Executive Hull Summary Table IX (iii), remark 2 · PDF p. 41 | not published the UR has no acceptance criteria section; its §8 is Reporting and Evaluation of Survey Contents §§7–8 · PDF p. 2 | not published Contents §§7–8 · PDF p. 2 | not published §5.7.3.7 asks only that representative readings be taken where uneven corrosion or pitting is found — PDF p. 21 Contents §§7–8 · PDF p. 2 |
| IACS UR Z10.3 Rev.21Chemical tankers — no CSR section | 20 % intensity — a reporting trigger, not an acceptance criterion Z10.3 carries the same remark as Z10.1. Bottom plating at 20 % intensity or above goes on the record once it is either wasted into the substantial corrosion band or pitted to an average depth of one third of the actual plate thickness or worse Table VII (iii), remark 2 · PDF p. 43 | not published the UR has no acceptance criteria section; its §8 is Reporting and Evaluation of Survey Contents §§7–8 · PDF p. 2 | not published Contents §§7–8 · PDF p. 2 | not published §5.7.3.7 asks only that representative readings be taken where uneven corrosion or pitting is found — PDF p. 22 Contents §§7–8 · PDF p. 2 |
| IACS CSR for Bulk Carriers and Oil Tankers1 January 2024 version, in force 1 July 2024 | not published the acceptance criteria section covers local corrosion against t_ren and global corrosion against the hull girder percentages, and nothing else Pt 1 Ch 13 Sec 2 [2] · PDF pp. 722–723 | not published the word pitting does not appear anywhere in the 812 pages Pt 1 Ch 13 Sec 2 [2] · PDF pp. 722–723 | not published Pt 1 Ch 13 Sec 2 [2] · PDF pp. 722–723 | not published CSR supplies t_ren, t_c and t_res; the pitting arithmetic that uses them is printed in UR Z10.2, Z10.4 and Z10.5, and [2.1.3] points at those URs by name for alternative solutions Pt 1 Ch 13 Sec 2 [2.1.3] · PDF p. 723 |
| IACS Rec 76 Rev.2Bulk carriers — a recommendation, not a requirement | guidance15 % intensity — the ceiling below which weld repair of pits is offered Figure 6 prints 5, 10 and 15 % scattered only — PDF p. 82 Area 3 §4.1.2 · PDF p. 81 | guidancenot published §2.1.4 says only that pitting may be found under coating blisters, which need to be removed before inspection — PDF p. 80 Area 3 §4.1 · PDF pp. 80–81 | guidancenot published the recommendation names the allowable diminution level as a drawing input for the surveyor's checklist rather than printing a percentage Area 3 §4.1 · PDF pp. 80–81 | guidancewhere intensity is below 15 %, pitting deeper than one quarter of the original thickness can be welded flush with the original surface; renew by plate insert where deep pits are clustered together or the remaining thickness is less than 6 mm a repair rule, not an acceptance criterion Area 3 §4.1.2 · PDF p. 81 |
| IACS Rec 96 Rev.2Double hull oil tankers — a recommendation, not a requirement | guidancenot published §3.4.4 is headed "Typical Corrosion Patterns" and runs from PDF p. 22; (c) Pitting Corrosion sits on p. 23. The recommendation describes pitting and its causes and gives no intensity threshold. The 300 mm figure on that page is a description of scabby patches in uncoated tanks, not a cleaning instruction §3.4.4 (c) · PDF pp. 22–23 | guidancenot published §3.4.4 (c) · PDF pp. 22–23 | guidancenot published Group 3 §5.1.2 · PDF p. 82 | guidancereplace plating under suction heads and sounding pipes once its average thickness has dropped under the acceptable limit; scattered deep pits can instead be made good by welding no percentage and no remaining-thickness figure appears anywhere in the 148 pages Group 1 §5.1.2 · PDF p. 53 |
| ABS Rules for Survey After Construction, Part 7July 2026 — Appendix 1 Section 4 | 15 % intensity CSR bulk carriers, single and double skin, in an area where coating is required. FIGURE 5 prints 5, 10, 15, 20 and 25 % scattered — PDF p. 605 7-A1-4/35.1.3(a) i) · PDF p. 598 | strip a patch at least 300 mm across, at the worst-pitted spot on the plate, down to bare metal; gauge the five deepest pits inside that patch; the thinnest of the five readings is the one booked 7-A1-4/35.1.3(a) i) · PDF p. 598 | the frame webs, the end bracket webs and their flanges keep 75 % of as-built; the side shell, hopper tank and topside tank plating each side frame lands on keeps 70 % of as-built, in a band reaching up to 30 mm out on either side of the frame without being greater than t_ren. The 75 % line carries a footnote on the same page: it does not apply to double skin bulk carriers 7-A1-4/35.1.3(a) i) · PDF p. 599 | t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two for plates with pitting intensity less than 20 %. The double hull oil tanker text at 7-A1-4/35.3.3(a) i), PDF p. 599, prints the same criterion. For non-CSR ships ABS prints no figure. Two clauses speak to it and they do not agree. 7-A1-4/5, PDF p. 582, leaves local wastage and pitting to the Surveyor to judge and says renewal may be needed; 7-A1-4/29, PDF p. 592, uses the same construction but says renewal may not be needed 7-A1-4/35.1.3(a) ii) · PDF p. 599 |
| BV NR467 Part AR26, July 2026 — Ch 2 App 3 | 15 % intensity for CSR bulk carriers; for ships not built under CSR the intensity is read off Fig 22 and used to set the acceptable pit depth the 15 % is based on pitting or grooving on one side of a plate only. Fig 22 prints 1, 3, 5, 10, 15, 20, 25, 30, 40 and 50 % scattered — PDF p. 155 [4.7.2] · PDF p. 155, and [4.6.2] · PDF p. 154 | strip a patch at least 300 mm across, at the worst-pitted spot on the plate, down to bare metal; gauge the five deepest pits inside that patch; the thinnest of the five readings is the one booked [4.7.2] · PDF p. 155 | on CSR bulk carriers of both hull forms, the side shell, hopper tank and topside tank plating each side frame lands on keeps 70 % of as-built, in a band reaching up to 30 mm out on either side of the frame; on CSR single skin bulk carriers, the frame webs, the end bracket webs and their flanges keep 75 % of as-built without being greater than t_ren. BV prints the same 75 % and 70 % pair a second time for single side skin bulk carriers outside CSR, under the retroactive side-frame requirements, where the trigger is again 15 % read off Fig 17 — Pt A Ch 6 App 1 [5.4.4], PDF pp. 415–416, and Pt A Ch 6 Sec 2 [5.3.3], PDF pp. 387–388 [4.7.2] · PDF p. 155 | t_m ≥ 0,7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1,0 — the lesser of the two for plates with pitting intensity less than 20 %, CSR bulk carriers and CSR oil tankers alike. For ships not built under CSR the criterion is a depth, not a thickness formula — see the intensity table below [4.7.3] · PDF p. 156 |
| CCS Guidelines for Thickness Measurement of HullVer 6.6, March 2025 — non-CSR criteria printed in full | 15 % intensity non-CSR single side skin bulk carriers complying with UR S31; the 15 % is based on pitting or grooving on one side of the web, and the intensity is assessed separately in each of zones A, B, C and D Part II §7.1.2 1) · PDF p. 28 | strip a patch of at least 300 mm diameter, at the worst-pitted spot, down to bare metal; gauge the five deepest pits inside that patch; the thinnest of the five readings is the one booked the appendix adds a length test the other societies do not print: remedial measures are called for where the total length of pitting inside the 300 mm diameter area is over 45 mm and the intensity is over 15 % — Appendix, PDF p. 85 Part II §7.1.2 1) · PDF p. 28 | against pitting, the cargo hold frame bracket webs and their flanges keep 75 % of as-built; the side shell, hopper tank and topside tank plating the cargo hold side frame lands on keeps 70 %, in a band reaching up to 30 mm out on either side of the frame for non-CSR bulk carriers. Structures other than the side structures take the same criteria — Part II §7.1.2 2), PDF p. 28 Part II §7.1.2 1) · PDF p. 28 | non-CSR oil tankers: 70 % of as-built where the member's general corrosion limit is 20 %, 65 % where it is 25 %, in both cases for pitting intensity less than 20 % and with no point below 6 mm; at 20 % intensity or more the general corrosion criteria apply the reference area for intensity is a single plate panel. For CSR ships the guideline prints no figure and refers out to CCS Rules Pt One Ch 5 Sec 1, 5.1.17, which is not held — Part III §2, PDF p. 31 Part II §§7.1.1.1–7.1.1.3 · PDF pp. 27–28 |
| KR Rules for the Classification of Steel Ships, Part 12026 edition — Ch 3 Sec 1 for CSR ships, Annex 1-5 for the rest | 15 % intensity CSR bulk carriers and double skin bulk carriers, in an area where coating is required. Fig 1.2.3 prints the intensity diagrams — Pt 1 Ch 2, PDF p. 32 Pt 1 Ch 3 Sec 1, 105. 2 (1)(A) · PDF p. 133 | strip a patch at least 300 mm across, at the worst-pitted spot on the plate, down to bare metal; gauge the five deepest pits inside that patch; the thinnest of the five readings is the one booked Pt 1 Ch 3 Sec 1, 105. 2 (1)(A) · PDF p. 133 | on single skin bulk carriers only, the frame webs, the end bracket webs and their flanges keep 75 % of as-built; the side shell, hopper tank and topside tank plating each side frame lands on keeps 70 % of as-built, in a band reaching up to 30 mm out on either side of the frame without being greater than the renewal thickness Pt 1 Ch 3 Sec 1, 105. 2 (1)(A) · PDF p. 133 | t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two for plates with pitting intensity less than 20 %. For ships not built under CSR, KR prints a flat wear limit for partial corrosion such as pitting: 30 % of the original thickness for Class I and 35 % for Class II — Annex 1-5 Table 1, PDF p. 277 Pt 1 Ch 3 Sec 1, 105. 2 (1)(B) · PDF p. 133 |
| PRSPublication 63/P for single side skin bulk carrier side frames; Part I, January 2026 for the rest | 15 % intensity single side skin bulk carriers and oil-bulk-ore carriers. Fig. 5 prints 5 % to 25 % intensity diagrams — PDF p. 16 §2.5 · PDF p. 10 | not published the clause calls for thickness measurement once 15 % is exceeded but prints no cleaning step and no five-deepest-pits step §2.5 · PDF p. 10 | one figure covers both defects: the frame webs, the bracket webs and their flanges keep 75 % of as-built; the side shell, hopper tank and topside tank plating the side frame lands on keeps 70 %, in a band reaching up to 30 mm out on either side of the frame the clause is headed Pitting and Grooving and gives one criterion for both defects. No cap against the renewal thickness is printed §2.5 · PDF p. 10 | not published the acceptance criteria for thickness measurements are those of the Rules and of the applicable IACS URs, which the clause names as UR S18, UR S21 and UR S21A; no pitting criterion is printed in Part I §5.1.3.6 · PDF p. 44 |
| INSB Rules and Regulations, Part IIssue 04 Rev.03, December 2024 — Ch 5 Sec 1 | 15 % intensity single skin and double side skin bulk carriers built under CSR, in an area where coating is required; the 15 % is based on pitting or grooving on one side of a plate only §1.13.1.1 · PDF p. 95 | strip a patch at least 300 mm across, at the worst-pitted spot on the plate, down to bare metal; gauge the five deepest pits inside that patch; the thinnest of the five readings is the one booked §1.13.1.1 · PDF p. 95 | single skin bulk carriers: the frame webs, the end bracket webs and their flanges keep 75 % of as-built, and the side shell, hopper tank and topside tank plating each side frame lands on keeps 70 % of as-built, in a band reaching up to 30 mm out on either side of the frame. Double skin bulk carriers: the 70 % figure only without being greater than t_ren. INSB is the one document here that splits the two hull forms into lettered sub-clauses instead of a footnote §1.13.1.1 a) · PDF p. 95, and §1.13.1.1 b) · PDF p. 96 | t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two for plates with pitting intensity less than 20 %. A second test runs alongside it: average the plating over any one cross section and that average must still make the CSR renewal thickness §1.13.1.2 · PDF p. 96 |
| ClassNK Guidance for Undergoing Class Maintenance Surveys2014 edition — Appendix 4-5 | older edition — 201415 % intensity side structures of bulk carriers built under CSR-B, in an area where coating is required Appendix 4-5 §5 (1)(c) i) · PDF p. 137 | older edition — 2014strip a patch at least 300 mm across, at the worst-pitted spot on the plate, down to bare metal; gauge the five deepest pits inside that patch; the thinnest of the five readings is the one booked Appendix 4-5 §5 (1)(c) i) · PDF p. 137 | older edition — 2014the frame webs, the end bracket webs and their flanges keep 75 % of as-built; the side shell, hopper tank and topside tank plating each side frame lands on keeps 70 % of as-built, in a band reaching up to 30 mm out on either side of the frame without being greater than t_ren. The clause covers pitting corrosion, grooving corrosion and other local areas together Appendix 4-5 §5 (1)(c) ii) · PDF p. 137 | older edition — 2014t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two for plates with pitting intensity less than 20 %, CSR-T and CSR-B ships. For ships outside CSR the guidance leaves pitting to the Surveyor and sets the standard limit for other local corrosion at 40 % of the original thickness — Appendix 4-5 §2 (1)(iv), PDF p. 131 Appendix 4-5 §5 (1)(a) · PDF p. 136 |
| RINA Part A Ch 2 App 21 July 2024 set — ships not built under CSR | older edition — 1 Jul 2024intensity is read off the Fig 12 diagrams and used to set the acceptable average pit depth; no gauging trigger is printed Fig 12 prints 1, 3, 5, 10, 15, 20, 25, 30, 40 and 50 % scattered — PDF p. 14 [4.5.2] · PDF p. 13 | older edition — 1 Jul 2024not published the appendix works on pit depth against as-built thickness and prints no cleaning or five-pit procedure [4.5] · PDF pp. 13–14 | older edition — 1 Jul 2024not published App 2 is the non-CSR appendix; the side-structure criteria for CSR bulk carriers sit in App 3 and are on the next row [4.5] · PDF pp. 13–14 | older edition — 1 Jul 2024an isolated pit may go 35 % deep into the as-built thickness; once the area is at 50 % intensity or above the pits there may average 20 % deep, with Tab 4 interpolating between the two in addition, the thickness outside the pits in the area considered is assessed against the local, global and buckling criteria of [4.3] and [4.4] — [4.5.3], PDF p. 14 [4.5.1] and [4.5.2] · PDF p. 13 |
| RINA Part A Ch 2 App 31 July 2024 set — CSR bulk carriers, single and double skin | older edition — 1 Jul 202415 % intensity single skin at [3.2.2], double skin at [4.2.2]; both point back at App 2 Fig 12 for the diagrams [3.2.2] a) · PDF p. 3, and [4.2.2] a) · PDF p. 9 | older edition — 1 Jul 2024strip a patch at least 300 mm across, at the worst-pitted spot on the plate, down to bare metal; gauge the five deepest pits inside that patch; the thinnest of the five readings is the one booked [3.2.2] a) · PDF p. 3 | older edition — 1 Jul 2024single skin: the frame webs, the end bracket webs and their flanges keep 75 % of as-built, and the side shell, hopper tank and topside tank plating each side frame lands on keeps 70 % of as-built, in a band reaching up to 30 mm out on either side of the frame. Double skin: the 70 % figure only without being greater than t_ren [3.2.2] a) · PDF p. 3, and [4.2.2] a) · PDF pp. 9–10 | older edition — 1 Jul 2024t_m > 0,7 (t_as-built − t_vol add), or t_m > t_ren − 1 mm — the lesser of the two for plates with pitting intensity less than 20 %. This set prints a strict inequality where the IACS URs print greater-than-or-equal [3.2.2] b) · PDF p. 3, and [4.2.2] b) · PDF p. 10 |
| DNV-CG-0182 Section 9Edition July 2022 — ships not built under CSR | older edition — Jul 202210 % intensity is the ceiling of the fixed criterion; intensity above 50 % is treated as 100 %, that is as general corrosion the 10 % ceiling is the lowest in this table; Figure 1 prints 5, 10, 20, 30 and 50 % scattered — PDF p. 28 Sec.9 [1.2] a) and d) · PDF p. 26 | older edition — Jul 2022not published instead of a gauging procedure the guideline gives a formula for the corrected average remaining thickness: t_act = t_plate (1 − Int/100) + t_pit · Int/100, where Int is the estimated pitting intensity in per cent — Sec.9 [1.3], PDF p. 26 Sec.9 [1] · PDF pp. 26–28 | older edition — Jul 2022not published single hull bulk carriers subject to ESP are referred out to DNV-RU-SHIP Pt.7 Ch.1 Sec.3 [2.3.4], which is not held Sec.9 [1.2] e) · PDF p. 26 | older edition — Jul 2022t_min = 0.6 t_as_built and not less than 6 mm, for plates with pitting intensity less than 10 %; at 100 % intensity the average remaining thickness in the worst cross section through the pitting is the general corrosion minimum; intermediate intensities may be accepted on linear interpolation between the two pitting repair by plastic compound filler is treated as a way to stop further corrosion and is not counted towards strength — Sec.9 [1.1], PDF p. 26 Sec.9 [1.2] a) to c) · PDF p. 26 |
| DNV-CG-0182 Section 10Edition July 2022 — CSR oil tankers and bulk carriers | older edition — Jul 202215 % intensity bulk carrier side structures where coating is required; the 15 % is based on pitting or grooving on one side of a plate only Sec.10 [2.2.2] · PDF p. 32 | older edition — Jul 2022strip a patch of at least 300 mm diameter, at the worst-pitted spot on the plate, down to bare metal; gauge the five deepest pits inside that patch; the thinnest of the five readings is the one booked this text says 300 mm diameter where UR Z10.2 §8.2.1 says 300 mm or more Sec.10 [2.2.2] · PDF p. 32 | older edition — Jul 2022on single side CSR bulk carriers only, the frame webs, the end bracket webs and their flanges keep 75 % of as-built; the side shell, hopper tank and topside tank plating each side frame lands on keeps 70 % of as-built, in a band reaching up to 30 mm out on either side of the frame without being greater than t_ren Sec.10 [2.2.2] · PDF p. 32 | older edition — Jul 2022t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 — the lesser of the two for plates with pitting intensity less than 20 %. A second test runs alongside it: average the plating over any one section and that average must still make the CSR general-corrosion renewal thickness Sec.10 [2.3] · PDF pp. 32–33 |
| LR Thickness Measurement and Close-up Survey Guidance, Part 1Ver 7.3, November 2016 — Ch 5 Sec 7 | older edition — Nov 2016 v7.315 % intensity CSR bulk carriers, in an area where coating is required; the 15 % is based on pitting or grooving on one side of a plate only §1.5.7.6 · PDF p. 40 | older edition — Nov 2016 v7.3strip a patch at least 300 mm across, at the worst-pitted spot on the plate, down to bare metal; gauge the five deepest pits inside that patch; the thinnest of the five readings is the one booked §1.5.7.6 · PDF p. 40 | older edition — Nov 2016 v7.3the frame webs, the end bracket webs and their flanges keep 75 % of as-built; the side shell, hopper tank and topside tank plating each side frame lands on keeps 70 % of as-built, in a band reaching up to 30 mm out on either side of the frame without being greater than t_renewal §1.5.7.6 · PDF p. 40 | older edition — Nov 2016 v7.3t_m ≥ 0.7 (t_as-built − t_own), or t_m ≥ t_renewal − 1 mm — the lesser of the two for CSR tankers, plates with pitting intensity less than 20 %. This document writes t_own for the owner's extra thickness where the IACS URs write t_vol add §1.5.7.6 · PDF p. 40 |
Pitting intensity against maximum average pitting depth — what each document prints
Two societies turn intensity into a number: BV and RINA print the same nine-step grid of intensity against maximum average pit depth, as a percentage of the as-built thickness, and it applies to ships not built under CSR. Everyone else prints intensity as pictures only — the scattered-percentage diagrams — and uses them to decide whether the 15 % or 20 % threshold has been passed. The third column names every diagram that draws each step, because the ranges differ and a step one document draws is a step another leaves out. 11 rows · every value carries its clause and PDF page
| Document · scope | BV — maximum average pitting depthTab 8, % of as-built thickness, ships not built under CSR | RINA — maximum acceptable average pitting depthTab 4, % of as-built thickness, ships not built under CSR | Which intensity diagrams draw this stepthe scattered-percentage pictures, document by document |
|---|---|---|---|
| Isolated pitsthe first line of both grids; a description, not a percentage | 35,0 [4.6.1] puts the same figure in words — an isolated pit may go 35 % deep into the as-built thickness and no deeper — PDF p. 154 Ch 2 App 3 Tab 8 · PDF p. 154 | older edition — 1 Jul 202435,0 [4.5.1] states the same figure in words — PDF p. 13 Ch 2 App 2 Tab 4 · PDF p. 13 | not published no diagram is drawn for isolated pits in any document here; the lowest step drawn anywhere is 1 % scattered Ch 2 App 3 Fig 22 · PDF p. 155 |
| 1 % | not published Tab 8 jumps from isolated straight to 5 %, although Fig 22 on the next page draws a 1 % diagram. [4.6.2] says intermediate values between isolated pits and 50 % are interpolated between 35 % and 20 % according to Tab 8 Ch 2 App 3 Tab 8 · PDF p. 154 | older edition — 1 Jul 2024not published same gap: Fig 12 draws 1 %, Tab 4 has no 1 % line Ch 2 App 2 Tab 4 · PDF p. 13 | BV NR467 Pt A Fig 22, PDF p. 155; RINA Pt A Ch 2 App 2 Fig 12, PDF p. 14 these are the only two figures in this table that go below 5 %. Both are headed from 1 % to 50 % intensity Ch 2 App 3 Fig 22 · PDF p. 155 |
| 3 % | not published drawn in Fig 22, absent from Tab 8 Ch 2 App 3 Tab 8 · PDF p. 154 | older edition — 1 Jul 2024not published drawn in Fig 12, absent from Tab 4 Ch 2 App 2 Tab 4 · PDF p. 13 | BV NR467 Pt A Fig 22, PDF p. 155; RINA Pt A Ch 2 App 2 Fig 12, PDF p. 14 Ch 2 App 3 Fig 22 · PDF p. 155 |
| 5 %the lowest step drawn by the IACS UR family | 33,5 Ch 2 App 3 Tab 8 · PDF p. 154 | older edition — 1 Jul 202433,5 Ch 2 App 2 Tab 4 · PDF p. 13 | twelve figures draw this step UR Z10.2 Figure 1 PDF p. 9; UR Z10.4 Figure 1 PDF p. 8; UR Z10.5 Figure 1 PDF p. 9; ABS FIGURE 5 PDF p. 605; BV Fig 22 PDF p. 155 and Pt A Ch 6 App 1 Fig 17 PDF p. 416; KR Fig 1.2.3 PDF p. 32; PRS Fig. 5 PDF p. 16; IACS Rec 76 Figure 6 PDF p. 82; RINA App 2 Fig 12 PDF p. 14; DNV-CG-0182 Sec.9 Figure 1 PDF p. 28 and Sec.10 Figure 1 PDF p. 33 Figure 1 · PDF p. 9 |
| 10 %the ceiling of the DNV non-CSR pitting criterion | 32,0 Ch 2 App 3 Tab 8 · PDF p. 154 | older edition — 1 Jul 202432,0 Ch 2 App 2 Tab 4 · PDF p. 13 | twelve figures draw this step the same twelve as the 5 % row: UR Z10.2, Z10.4, Z10.5, ABS FIGURE 5, BV Fig 22 and Fig 17, KR Fig 1.2.3, PRS Fig. 5, Rec 76 Figure 6, RINA App 2 Fig 12, DNV Sec.9 Figure 1 and Sec.10 Figure 1 Figure 1 · PDF p. 9 |
| 15 %the intensity at which the CSR side-structure rule calls for gauging | 30,5 the 30,5 % depth is a non-CSR figure and is unrelated to the 15 % gauging trigger of [4.7.2], which is a CSR clause Ch 2 App 3 Tab 8 · PDF p. 154 | older edition — 1 Jul 202430,5 Ch 2 App 2 Tab 4 · PDF p. 13 | eleven figures draw this step the twelve of the 10 % row less DNV-CG-0182 Sec.9 Figure 1, which jumps from 10 % to 20 % — PDF p. 28. Rec 76 Figure 6 stops here: it is headed from 5 % to 15 % intensity Figure 1 · PDF p. 9 |
| 20 %the ceiling of the CSR other-structures criterion | 29,0 Ch 2 App 3 Tab 8 · PDF p. 154 | older edition — 1 Jul 202429,0 Ch 2 App 2 Tab 4 · PDF p. 13 | eleven figures draw this step the twelve of the 10 % row less IACS Rec 76 Figure 6, which stops at 15 % — PDF p. 82 Figure 1 · PDF p. 9 |
| 25 %the top of the IACS UR and ABS diagram ranges | 27,5 Ch 2 App 3 Tab 8 · PDF p. 154 | older edition — 1 Jul 202427,5 Ch 2 App 2 Tab 4 · PDF p. 13 | ten figures draw this step UR Z10.2, Z10.4, Z10.5, ABS FIGURE 5, BV Fig 22 and Fig 17, KR Fig 1.2.3, PRS Fig. 5, RINA App 2 Fig 12, DNV Sec.10 Figure 1. Rec 76 Figure 6 and DNV Sec.9 Figure 1 do not draw it Figure 1 · PDF p. 9 |
| 30 % | 26,0 Ch 2 App 3 Tab 8 · PDF p. 154 | older edition — 1 Jul 202426,0 Ch 2 App 2 Tab 4 · PDF p. 13 | BV NR467 Pt A Fig 22, PDF p. 155; RINA Pt A Ch 2 App 2 Fig 12, PDF p. 14; DNV-CG-0182 Sec.9 Figure 1, PDF p. 28 above 25 % only the three non-CSR figures carry on Ch 2 App 3 Fig 22 · PDF p. 155 |
| 40 % | 23,0 Ch 2 App 3 Tab 8 · PDF p. 154 | older edition — 1 Jul 202423,0 Ch 2 App 2 Tab 4 · PDF p. 13 | BV NR467 Pt A Fig 22, PDF p. 155; RINA Pt A Ch 2 App 2 Fig 12, PDF p. 14 DNV-CG-0182 Sec.9 Figure 1 has no 40 % step; it goes 30 % then 50 % Ch 2 App 3 Fig 22 · PDF p. 155 |
| 50 % and abovethe last line of both grids | 20,0 [4.6.2] puts the rule in words: once an area is at 50 % intensity or above, the pits there may average 20 % of the as-built thickness deep and no more — PDF p. 154 Ch 2 App 3 Tab 8 · PDF p. 154 | older edition — 1 Jul 202420,0 [4.5.2] prints the same rule in words — PDF p. 13 Ch 2 App 2 Tab 4 · PDF p. 13 | BV NR467 Pt A Fig 22, PDF p. 155; RINA Pt A Ch 2 App 2 Fig 12, PDF p. 14; DNV-CG-0182 Sec.9 Figure 1, PDF p. 28 DNV treats intensity above 50 % as 100 %, that is as general corrosion — Sec.9 [1.2] d), PDF p. 26 Ch 2 App 3 Fig 22 · PDF p. 155 |
- grid
- The BV and RINA grids carry identical values at every one of the nine steps. Both are non-CSR criteria and both work on pit depth against as-built thickness, not on a remaining-thickness formula. Ch 2 App 3 Tab 8 · PDF p. 154, and RINA Pt A Ch 2 App 2 Tab 4 · PDF p. 13
- outside
- The depth grid is not the whole test. For ships contracted for construction before 1 July 2022, BV also requires the thickness outside the pits in the area considered to be assessed against [4.3] and [4.4]; RINA prints the same second test without the contract-date condition. Ch 2 App 3 [4.6.3] · PDF p. 154, and RINA [4.5.3] · PDF p. 14
- filler
- Both documents print the same note on filler. Plastic or epoxy compound is recommended as a way to halt or slow the process, but it does not count as a repair once the pitting is past the allowable wastage limits. Welded repairs can be accepted where the procedure has been agreed with the society. Ch 2 App 3 [4.6.3] Note 1 · PDF p. 154
- no grid
- ABS prints no depth grid at all. 7-A1-4/35.3 FIGURE 5 is five diagrams — 5, 10, 15, 20 and 25 % scattered — and the only numbers ABS attaches to intensity are the 15 % gauging trigger and the 20 % ceiling of the individual-measurement criterion, both of which are CSR clauses. 7-A1-4/35.3 FIGURE 5 · PDF p. 606
Grooving corrosion — the groove size the rule covers, and the thickness left in it
A groove is judged on its breadth first. Under the CSR wording a groove up to 15 % of the web height and up to 30 mm gets its own remaining-thickness figure; anything wider is thrown back to the general corrosion criteria and read as an average across the member. Two documents break that pattern with their own numbers: DNV runs to 100 mm on non-CSR ships and prints a separate figure for L-profiles, and CCS prints a second criterion for a corroded weld seam on shell plating. 20 rows · every value carries its clause and PDF page
| Document · scope | Groove size the criterion coversbreadth against web height, and the absolute cap | Accepted remaining thickness in the grooveand the floor, where one is printed | Grooves larger than thatwhat the clause sends you to |
|---|---|---|---|
| IACS UR Z10.2 Rev.37Single side skin bulk carriers — §8.4 applies to CSR ships only | grooves no broader than 30 mm, and no broader than 15 % of the web height Figure 3 dimensions the groove breadth twice on the same detail: across the attached plating either side of the weld, and down the web of the flat bar stiffener — PDF p. 10 §8.4.1 · PDF p. 43 | t_m ≥ 0.75 (t_as-built − t_vol add), or t_m ≥ t_ren − 0.5 mm — the lesser of the two, but not less than t_m = 6 mm the 6 mm floor overrides both formulas; a thin member can fail on it alone §8.4.1 · PDF p. 43 | assessed on the general corrosion criteria of CSR Ch 13, read as the mean thickness across the whole plate or stiffener the local groove figure is withdrawn, not relaxed — the member is then read as an average §8.4.2 · PDF p. 44 |
| IACS UR Z10.5 Rev.20Double side skin bulk carriers — §8.4 applies to CSR ships only | grooves no broader than 30 mm, and no broader than 15 % of the web height Figure 3, PDF p. 10 §8.4.1 · PDF p. 42 | t_m ≥ 0.75 (t_as-built − t_vol add), or t_m ≥ t_ren − 0.5 mm — the lesser of the two, but not less than t_m = 6 mm §8.4.1 · PDF p. 42 | assessed on the general corrosion criteria of CSR Ch 13, read as the mean thickness across the whole plate or stiffener §8.4.2 · PDF p. 42 |
| IACS UR Z10.4 Rev.18Double hull oil tankers — §8.4 applies to CSR ships only | grooves no broader than 30 mm, and no broader than 15 % of the web height Figure 3, PDF p. 9. The tanker UR carries the grooving section in full even though it carries no side-structure pitting clause §8.4.1 · PDF p. 36 | t_m ≥ 0.75 (t_as-built − t_vol add), or t_m ≥ t_ren − 0.5 mm — the lesser of the two, but not less than t_m = 6 mm t_ren is the general corrosion renewal criterion of CSR Pt 1 Ch 13 Sec 2 [2.1.1], or of Section 12 [1.4.2.1] for a ship built under the older CSR for Oil Tankers §8.4.1 · PDF p. 36 | assessed on the general corrosion criteria of CSR, read as the mean thickness across the whole plate or stiffener §8.4.2 · PDF p. 36 |
| IACS UR Z10.1 Rev.25Oil tankers, ore/oil ships — no CSR section | not published grooving appears once in the 92 pages, inside the repair clause listing damage in association with wastage over the allowable limits; the UR has no acceptance criteria section §1.3.1 · PDF p. 7 | not published Contents §§7–8 · PDF p. 2 | not published Contents §§7–8 · PDF p. 2 |
| IACS UR Z10.3 Rev.21Chemical tankers — no CSR section | not published grooving appears once in the 63 pages, in the same repair clause; the UR has no acceptance criteria section §1.3.1 · PDF p. 8 | not published Contents §§7–8 · PDF p. 2 | not published Contents §§7–8 · PDF p. 2 |
| IACS CSR for Bulk Carriers and Oil Tankers1 January 2024 version, in force 1 July 2024 | not published the single occurrence of grooving in the 812 pages is wire rope grooving at cargo hold openings, a newbuilding clause calling for half-round bar protection on hatch side girders, hatch end beams and the upper portion of hatch coamings Pt 2 Ch 1 Sec 2 [3.3.5] · PDF p. 739 | not published the renewal chapter runs to local corrosion against t_ren and global corrosion against the hull girder percentages, and stops there Pt 1 Ch 13 Sec 2 [2] · PDF pp. 722–723 | not published the grooving arithmetic that uses t_ren and t_c is printed in UR Z10.2 §8.4, Z10.4 §8.4 and Z10.5 §8.4, and [2.1.3] points at those URs by name Pt 1 Ch 13 Sec 2 [2.1.3] · PDF p. 723 |
| IACS Rec 76 Rev.2Bulk carriers — a recommendation, not a requirement | guidancenot published the recommendation describes where grooving forms — at the transition between the thicker deck plating outside the line of cargo hatches and the thinner cross deck plating, where the step in thickness gathers water — and prints no breadth limit Area 1 §2.1.2 · PDF p. 30 | guidancenot published the corrosion section explains the mechanism, a galvanic current between the heat affected zone and the base metal, and gives no thickness figure §3.3.2 Material wastage · PDF p. 15 | guidancerenewing the adjacent cross deck plating, in part or across its full width, is what the recommendation says to consider; an isolated groove on a side shell frame may be built back up by welding a repair rule, not an acceptance criterion Area 1 §4.1.1 · PDF p. 33, and Area 3 Examples 3 and 5 · PDF pp. 86, 88 |
| IACS Rec 96 Rev.2Double hull oil tankers — a recommendation, not a requirement | guidancenot published Figure 8 on PDF p. 23 is headed Grooving Corrosion and labels the groove breadth on the attached plating and on a flat bar stiffener, the same drawing the URs use — but no number is set against it §3.4.4 (b) · PDF pp. 22–23 | guidancenot published §3.4.4 (b) · PDF pp. 22–23 | guidancenot published the text is descriptive: severe grooving along the welding of bottom plating is often found, accelerated by poor maintenance of the coating or of the sacrificial anodes Group 3 §4.1.2 · PDF p. 81 |
| ABS Rules for Survey After Construction, Part 7July 2026 — Appendix 1 Section 4 | grooves no broader than 30 mm, and no broader than 15 % of the web height CSR bulk carriers. The double hull oil tanker text at 7-A1-4/35.3.3(c) i), PDF p. 600, prints the same limit. FIGURE 4, Example of Grooving Corrosion, is on PDF p. 604 7-A1-4/35.1.3(c) i) · PDF p. 599 | t_m ≥ 0.75 (t_as-built − t_vol add), or t_m ≥ t_ren − 0.5 mm — the lesser of the two, but not less than t_m = 6 mm t_ren is the renewal criterion for general corrosion of CSR Pt 5A Pt 1 Ch 13 Sec 2 [2.1.1] 7-A1-4/35.1.3(c) i) · PDF pp. 599–600 | assessed on the general corrosion criteria of CSR Pt 5A Pt 1 Ch 13, read as the mean thickness across the whole plate or stiffener for ships outside CSR, ABS prints no grooving figure. 7-A1-4/29 says only that badly wasted, pitted or grooved patches may need attention at once, and leaves local wastage and pitting to the Surveyor to judge — PDF p. 592 7-A1-4/35.1.3(c) ii) · PDF p. 600 |
| BV NR467 Part AR26, July 2026 — Ch 2 App 3 | grooves no broader than 30 mm, and no broader than 15 % of the web height CSR ships. Figure 24, Grooving corrosion, is on the same page [4.7.5] a) · PDF p. 157 | t_m ≥ 0,75 (t_as-built − t_vol add), or t_m ≥ t_ren − 0,5 — the lesser of the two, but not less than t_m = 6 mm [4.7.5] a) · PDF p. 157 | assessed on the general corrosion criteria of NR522 Ch 13, NR523 Section 12 or NR606 Pt 1 Ch 13 as applicable, read as the mean thickness across the whole plate or stiffener for ships not built under CSR, App 3 [4.3.4] a) treats grooving of a plate or web through the isolated-area criterion of the diminution tables rather than through a groove-breadth rule — PDF p. 145 [4.7.5] b) · PDF p. 157 |
| CCS Guidelines for Thickness Measurement of HullVer 6.6, March 2025 — non-CSR criteria printed in full | groove width not exceeding 15 % of the web plate height and not exceeding 30 mm, and two conditions on top: the groove and its edge are smooth with no sharp concave or convex, and the weld seam is complete with an acceptable surplus welding throat thickness non-CSR ships. CCS is the only document here that makes the shape of the groove and the state of the weld a condition of the criterion rather than an assumption stated elsewhere Part II §7.3 · PDF p. 30 | web and face plate: t_min = 0.75 T_as-built, but not less than 6.00 mm. Corroded weld seam on shell plating: t_min = 0.7 T_as-built, where the groove breadth adjacent to the framing knuckle weld is not more than 30 mm the second figure is a separate criterion for the weld seam itself, not a relaxation of the first Part II §7.3 1) and 2) · PDF p. 30 | not published for CSR ships the guideline prints no figure and refers out to CCS Rules Pt One Ch 5 Sec 1, 5.1.17(4), which is not held. A separate reporting duty applies: separate diagrams of grooving corrosion are to be drawn, showing the least remaining thickness, the influenced areas, the percentage and the length of the grooving — Part II §7.3, PDF p. 31 Part III §4 · PDF p. 31 |
| KR Rules for the Classification of Steel Ships, Part 12026 edition — Ch 3 Sec 1 for CSR ships | grooves no broader than 30 mm, and no broader than 15 % of the web height the clause points at Pt 1 Ch 2 Fig 1.2.5 for the drawing — PDF p. 33 Pt 1 Ch 3 Sec 1, 105. 2 (3)(A) · PDF p. 134 | t_m ≥ 0.75 (t_as-built − t_vol add), or t_m ≥ t_ren − 0.5 mm — the lesser of the two, but not less than 6 mm the symbols are not repeated; the clause refers back to 105. 2 (1)(B), the pitting criterion for other structures Pt 1 Ch 3 Sec 1, 105. 2 (3)(A) · PDF p. 134 | assessed on the general corrosion criteria of CSR Ch 13 as applicable, read as the mean thickness across the whole plate or stiffener for ships not built under CSR, KR prints no groove-breadth rule; Annex 1-5 Table 1 sets one flat wear limit for partial corrosion such as pitting, 30 % of the original thickness for Class I and 35 % for Class II — PDF p. 277 Pt 1 Ch 3 Sec 1, 105. 2 (3)(B) · PDF p. 134 |
| PRSPublication 63/P for single side skin bulk carrier side frames; Part I, January 2026 for the rest | not published the clause is headed Pitting and Grooving and gives one remaining-thickness criterion for both defects; no groove breadth and no web-height fraction is printed §2.5 · PDF p. 10 | one figure covers both defects: the frame webs, the bracket webs and their flanges keep 75 % of as-built; the side shell, hopper tank and topside tank plating the side frame lands on keeps 70 %, in a band reaching up to 30 mm out on either side of the frame single side skin bulk carriers and oil-bulk-ore carriers. No cap against the renewal thickness is printed and no 6 mm floor is printed §2.5 · PDF p. 10 | not published Part I names grooving only in the repair clause, among damage in association with wastage over the allowable limits, and again in the survey planning meeting list of findings to report promptly — §5.1.3.1, PDF p. 43 §5.1.1.13 · PDF p. 40 |
| INSB Rules and Regulations, Part IIssue 04 Rev.03, December 2024 — Ch 5 Sec 1 | grooves no broader than 30 mm, and no broader than 15 % of the web height CSR ships. The clause says see Figure 3, but no Figure 3 is printed in the section §1.13.3.1 · PDF p. 96 | t_m ≥ 0.75 (t_as-built − t_vol add), or t_m ≥ t_ren − 0.5 mm — the lesser of the two, but not less than t_m = 6 mm §1.13.3.1 · PDF p. 96 | assessed on the general corrosion criteria of the IACS Common Structural Rules, read as the mean thickness across the whole plate or stiffener §1.13.3.2 · PDF p. 96 |
| ClassNK Guidance for Undergoing Class Maintenance Surveys2014 edition — Appendix 4-5 | older edition — 2014grooves no broader than 30 mm, and no broader than 15 % of the web height CSR-T and CSR-B ships Appendix 4-5 §5 (3)(a) · PDF p. 137 | older edition — 2014t_m ≥ 0.75 (t_as-built − t_vol add), or t_m ≥ t_ren − 0.5 mm — the lesser of the two, but not less than 6 mm this text places the 6 mm floor ahead of the two formulas rather than after them; the arithmetic is the same Appendix 4-5 §5 (3)(a) · PDF pp. 137–138 | older edition — 2014assessed on the general corrosion criteria of Chapter 13 Part CSR-B or Section 12 Part CSR-T, read as the mean thickness across the whole plate or stiffener for ships outside CSR the guidance prints no groove criterion; the standard limit for other local corrosion is 40 % of the original thickness — Appendix 4-5 §2 (1)(iv), PDF p. 131 Appendix 4-5 §5 (3)(b) · PDF p. 138 |
| RINA Part A Ch 2 App 21 July 2024 set — ships not built under CSR | older edition — 1 Jul 2024not published the appendix has no grooving section. Grooving is named as an example of what the isolated-area criterion is for: a very local aspect such as grooving of a plate or web, or local severe corrosion [4.3.4] a) · PDF p. 12 | older edition — 1 Jul 2024read from column 1, isolated areas, of the diminution table for the ship type and contract date; no single grooving percentage is printed the same clause excludes pitting from the isolated-area column and sends it to [4.5] instead, so the two defects are read from different places [4.3.4] a) and [4.3.5] a) · PDF p. 12 | older edition — 1 Jul 2024fail the isolated-area criterion and the wasted patch has to be attended to as needed; the item then moves on to column 2 and is judged on its average thickness [4.3.5] a) and b) · PDF p. 12 |
| RINA Part A Ch 2 App 31 July 2024 set — CSR bulk carriers and CSR double hull oil tankers | older edition — 1 Jul 2024grooves no broader than 30 mm, and no broader than 15 % of the web height printed three times, once for single skin bulk carriers, once for double skin bulk carriers and once for double hull oil tankers; all three point at Sec 2, Fig 2 for the drawing [3.2.4] a) · PDF p. 9, [4.2.4] a) · PDF p. 15, and [5.2.4] a) · PDF p. 20 | older edition — 1 Jul 2024t_m > 0,75 (t_as-built − t_vol add), or t_m > t_ren − 0,5 — the lesser of the two, but not less than t_m = 6 mm this set prints a strict inequality where the IACS URs print greater-than-or-equal [3.2.4] a) · PDF p. 9, [4.2.4] a) · PDF p. 15, and [5.2.4] a) · PDF p. 20 | older edition — 1 Jul 2024assessed on the general corrosion criteria of CSR Chapter 13, or Section 12 for a double hull oil tanker under the older CSR, read as the mean thickness across the whole plate or stiffener [3.2.4] b) · PDF p. 9, and [5.2.4] b) · PDF p. 20 |
| DNV-CG-0182 Section 9Edition July 2022 — ships not built under CSR | older edition — Jul 2022grooves no broader than 100 mm, and no broader than 15 % of the web height the 100 mm cap is more than three times the 30 mm the CSR wording allows, and applies only to ships outside CSR. [2.2] attaches assumptions to it: the groove and its edges have to be smooth, with no sharp edge or notch, and the weld has to be sound with an acceptable throat left Sec.9 [2.3] · PDF p. 29 | older edition — Jul 2022t_min = 0.7 t_as_built, and t_min = 0.75 t_as_built for L-profiles, in both cases not less than 6.0 mm. Corroded welded seams in shell plating carry their own figure: t_min = 0.7 t_as_built the only document here that sets a different figure for an L-profile Sec.9 [2.3] and [2.4] · PDF p. 29 | older edition — Jul 2022a length cap rather than a thickness one. Transverse grooves are added up over the cargo area — deck, bottom, longitudinal bulkhead, side plating — and the total may not pass 20 % of the breadth of the ship, or of its height where height is the dimension that answers. Where the deck is largely open, a container ship for instance, grooves running across the passageway may not add up past 10 % of the breadth a length test no other document in this table prints. [2.2] fixes what is being added up: every groove on a given structural member, its lengths summed, across deck, bottom, longitudinal bulkhead and side plating inside the cargo area — Sec.9 [2.2], PDF p. 29 Sec.9 [2.3] and [2.4] · PDF p. 29 |
| DNV-CG-0182 Section 10Edition July 2022 — CSR oil tankers and bulk carriers | older edition — Jul 2022grooves no broader than 30 mm, and no broader than 15 % of the web height Figure 3, Groove corrosion, is on PDF p. 35. The same guideline therefore carries two different caps — 100 mm in Sec.9 and 30 mm here — and the CSR status of the ship decides which one is read Sec.10 [4.1] · PDF p. 34 | older edition — Jul 2022t_m ≥ 0.75 (t_as-built − t_vol add), or t_m ≥ t_ren − 0.5 — the lesser of the two, but not less than t_m = 6 Sec.10 [4.1] · PDF pp. 34–35 | older edition — Jul 2022assessed on the general corrosion criteria of IACS CSR, read as the mean thickness across the whole plate and stiffener Sec.10 [4.2] · PDF p. 35 |
| LR Thickness Measurement and Close-up Survey Guidance, Part 1Ver 7.3, November 2016 — Ch 5 Sec 7 | older edition — Nov 2016 v7.3grooves no broader than 30 mm, and no broader than 15 % of the web height the criterion is printed under the heading CSR Tankers only. The pitting part of the same clause carries a CSR Bulk Carriers heading as well; the grooving part does not §1.5.7.6, Grooving Corrosion · PDF p. 41 | older edition — Nov 2016 v7.3t_m ≥ 0.75 (t_as-built − t_own), or t_m ≥ t_renewal − 0.5 mm — the lesser of the two, but not less than t_m = 6 mm this document writes t_own for the owner's extra thickness where the IACS URs write t_vol add §1.5.7.6 · PDF p. 41 | older edition — Nov 2016 v7.3where the grooving runs wider than that, the member is judged on the general corrosion criteria, read as the mean thickness across the whole plate or stiffener the same section defines local corrosion by listing its forms: pits, grooves, corroded edges, necking, and anything else of a strictly local character — §1.5.7.4, PDF p. 38 §1.5.7.6 · PDF p. 41 |
Edge corrosion — the corroded height the rule covers, the thickness left, and the openings clause
Edge corrosion is two rules in one clause. The first covers the free edge of a stiffener flange, or the web of a flat bar, and gates on how far down the edge the corrosion runs. The second covers plate edges at manholes and lightening holes, and gates on how far in from the opening the thin band reaches. Both are printed together everywhere they appear. CCS and DNV write the edge-thickness limit as a fraction of the as-built thickness where the CSR wording writes a formula against t_ren. 20 rows · every value carries its clause and PDF page
| Document · scope | Corroded edge the criterion coverscorroded height against flange breadth or web height | Accepted remaining thicknessat the edge, and averaged across the stiffener | Plate edges at manholes and lightening holeshow far below the minimum an edge may go, and cropping back |
|---|---|---|---|
| IACS UR Z10.2 Rev.37Single side skin bulk carriers — §8.3 applies to CSR ships only | corrosion working along a free edge may take in under a quarter of the member: less than 25 % of the flange breadth, or — where the stiffener is a flat bar — less than 25 % of the web height Figure 2 dimensions 0.25 h_stf down the web of a flat bar and 0.25 b_stf along the flange of an inverted angle or built-up stiffener — PDF p. 9 §8.3.1 · PDF p. 43 | t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two; and the mean thickness taken right across the stiffener, over its flange breadth or its web height, must still reach the figure set by CSR Ch 13 two tests, both to be met: the local reading at the edge and the average across the member §8.3.1 and §8.3.2 · PDF p. 43 | a plate edge at a manhole or lightening hole is allowed to sit under the rule minimum on two conditions. The thinned band must run inward from that edge over 20 % at most of the opening's smallest dimension, and never beyond 100 mm. A ragged edge may be trimmed, so long as the trimming enlarges the opening's largest dimension by 10 % at most and leaves the fresh edge at t_ren − 1 mm or thicker the 20 % and the 100 mm are both ceilings; the smaller one governs §8.3.3 (a) and (b) · PDF p. 43 |
| IACS UR Z10.5 Rev.20Double side skin bulk carriers — §8.3 applies to CSR ships only | corrosion working along a free edge may take in under a quarter of the member: less than 25 % of the flange breadth, or — where the stiffener is a flat bar — less than 25 % of the web height Figure 2, PDF p. 9 §8.3.1 · PDF p. 42 | t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two; and the mean thickness taken right across the stiffener, over its flange breadth or its web height, must still reach the figure set by CSR Ch 13 §8.3.1 and §8.3.2 · PDF p. 42 | a plate edge at a manhole or lightening hole is allowed to sit under the rule minimum on two conditions. The thinned band must run inward from that edge over 20 % at most of the opening's smallest dimension, and never beyond 100 mm. A ragged edge may be trimmed, so long as the trimming enlarges the opening's largest dimension by 10 % at most and leaves the fresh edge at t_ren − 1 mm or thicker §8.3.3 (a) and (b) · PDF p. 42 |
| IACS UR Z10.4 Rev.18Double hull oil tankers — §8.3 applies to CSR ships only | corrosion working along a free edge may take in under a quarter of the member: less than 25 % of the flange breadth, or — where the stiffener is a flat bar — less than 25 % of the web height Figure 2, PDF p. 8 §8.3.1 · PDF p. 35 | t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two; and the mean thickness taken right across the stiffener, over its flange breadth or its web height, must still reach the figure set by IACS CSR t_ren here is the general-corrosion renewal criterion — Section 12 [1.4.2.1] of the older CSR for Oil Tankers, or Pt 1 Ch 13 Sec 2 [2.1.1] of CSR BC & OT §8.3.1 · PDF p. 35, and §8.3.2 · PDF p. 36 | a plate edge at a manhole or lightening hole is allowed to sit under the rule minimum on two conditions. The thinned band must run inward from that edge over 20 % at most of the opening's smallest dimension, and never beyond 100 mm. A ragged edge may be trimmed, so long as the trimming enlarges the opening's largest dimension by 10 % at most and leaves the fresh edge at t_ren − 1 mm or thicker §8.3.3 a) and b) · PDF p. 36 |
| IACS UR Z10.1 Rev.25Oil tankers, ore/oil ships — no CSR section | not published the term edge corrosion does not appear anywhere in the 92 pages; the definitions of §1.2 run from substantial corrosion to prompt and thorough repair and name no local-corrosion type — PDF pp. 6–7 Contents §§7–8 · PDF p. 2 | not published the UR has no acceptance criteria section; its §8 is Reporting and Evaluation of Survey Contents §§7–8 · PDF p. 2 | not published Contents §§7–8 · PDF p. 2 |
| IACS UR Z10.3 Rev.21Chemical tankers — no CSR section | not published the term edge corrosion does not appear anywhere in the 63 pages Contents §§7–8 · PDF p. 2 | not published the UR has no acceptance criteria section Contents §§7–8 · PDF p. 2 | not published Contents §§7–8 · PDF p. 2 |
| IACS CSR for Bulk Carriers and Oil Tankers1 January 2024 version, in force 1 July 2024 | not published the term edge corrosion does not appear anywhere in the 812 pages Pt 1 Ch 13 Sec 2 [2] · PDF pp. 722–723 | not published the acceptance criteria are local corrosion against t_ren and global corrosion against the hull girder percentages, and nothing else Pt 1 Ch 13 Sec 2 [2] · PDF pp. 722–723 | not published the edge arithmetic that uses t_ren is printed in UR Z10.2 §8.3, Z10.4 §8.3 and Z10.5 §8.3, and [2.1.3] points at those URs by name Pt 1 Ch 13 Sec 2 [2.1.3] · PDF p. 723 |
| IACS Rec 76 Rev.2Bulk carriers — a recommendation, not a requirement | guidancenot published the term edge corrosion does not appear anywhere in the recommendation; the material wastage clause names general corrosion, grooving corrosion and pitting corrosion and stops there §3.3.2 Material wastage · PDF p. 15 | guidancenot published §3.3.2 Material wastage · PDF p. 15 | guidancenot published the nearest the text comes is the hatch corner discussion, which treats a welded attachment or shedder plate close to a free edge as a fracture initiator rather than a wastage criterion — Area 1 §2.3.3 (c), PDF p. 31 §3.3.2 Material wastage · PDF p. 15 |
| IACS Rec 96 Rev.2Double hull oil tankers — a recommendation, not a requirement | guidancenot published the recommendation only defines the term: corrosion working locally at the free edge of a plate, a stiffener or a primary support member, and round openings. It points at Figure 9 on PDF p. 24 and sets no percentage against either §3.4.4 (d) · PDF p. 23 | guidancenot published §3.4.4 (d) · PDF p. 23 | guidancenot published the text names structure in way of lightening holes or cut-outs as a place where accelerated corrosion is experienced from local drainage and flow, and gives no acceptance figure §3.4.6 · PDF p. 27 |
| ABS Rules for Survey After Construction, Part 7July 2026 — Appendix 1 Section 4 | corrosion working along a free edge may take in under a quarter of the member: less than 25 % of the flange breadth, or — where the stiffener is a flat bar — less than 25 % of the web height CSR bulk carriers. The double hull oil tanker text at 7-A1-4/35.3.3(b) i), PDF p. 599, prints the same limit. FIGURE 3, Example of Edge Corrosion, is on PDF p. 603 7-A1-4/35.1.3(b) i) · PDF p. 599 | t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two; and the mean thickness taken right across the stiffener, over its flange breadth or its web height, must still reach the figure set by CSR Pt 5A Pt 1 Ch 13 7-A1-4/35.1.3(b) i) and ii) · PDF p. 599 | a plate edge at a manhole or lightening hole is allowed to sit under the rule minimum on two conditions. The thinned band must run inward from that edge over 20 % at most of the opening's smallest dimension, and never beyond 100 mm. A ragged edge may be trimmed, so long as the trimming enlarges the opening's largest dimension by 10 % at most and leaves the fresh edge at t_ren − 1 mm or thicker the tanker version of this bullet at 7-A1-4/35.3.3(b) iii), PDF p. 600, points the reduced-thickness limit at Section 12 [1.4.2] of the older CSR for Oil Tankers, while the sentence around it points at CSR Pt 5A Pt 1 Ch 13 Sec 2 [2] — the same figure cited to two editions 7-A1-4/35.1.3(b) iii) · PDF p. 599 |
| BV NR467 Part AR26, July 2026 — Ch 2 App 3 | corrosion working along a free edge may take in under a quarter of the member: less than 25 % of the flange breadth, or — where the stiffener is a flat bar — less than 25 % of the web height CSR ships. Figure 23, Edge corrosion, is on the same page [4.7.4] · PDF p. 156 | t_m ≥ 0,7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1,0 — the lesser of the two; and the mean thickness taken right across the stiffener, over its flange breadth or its web height, must still reach the figure set by NR522 Ch 13, NR523 Section 12 or NR606 Pt 1 Ch 13, whichever applies [4.7.4] · PDF p. 156 | a plate edge at a manhole or lightening hole is allowed to sit under the rule minimum on two conditions. The thinned band must run inward from that edge over 20 % at most of the opening's smallest dimension, and never beyond 100 mm. A ragged edge may be trimmed, so long as the trimming enlarges the opening's largest dimension by 10 % at most and leaves the fresh edge at t_ren − 1 mm or thicker for ships not built under CSR, App 3 prints no edge corrosion criterion; edge corrosion is defined in Ch 2 Sec 2 [2.2.9] and pointed at Ch 2 App 3 Fig 15 — PDF p. 107 [4.7.4] a) and b) · PDF p. 156 |
| CCS Guidelines for Thickness Measurement of HullVer 6.6, March 2025 — non-CSR criteria printed in full | a fractured edge, or a flat bar longitudinal: corrosion may take in under 25 % of the web plate height of the longitudinal non-CSR ships Part II §7.2 1) · PDF p. 29 | edge thickness not less than 2/3 T_as-built, and the average thickness of the longitudinal not less than the uniform corrosion limit 2/3 is about 66.7 %, close to but not the same as the 0.7 (t_as-built − t_vol add) of the CSR wording, and it is set against the as-built thickness with no voluntary addition deducted Part II §7.2 1) · PDF p. 29 | edge thickness not less than 1/3 T_as-built and uniform; the corroded edge may not extend more than 20 % of the minimum size of the opening and not more than 100 mm; the corroded edge may be cropped and repaired so long as the largest increase of opening size does not exceed 10 % of its area CCS caps the cropping at 10 % of the area of the opening; the IACS wording caps it at 10 % of the maximum dimension. For CSR ships the guideline prints no figure and refers out to CCS Rules Pt One Ch 5 Sec 1, 5.1.17(3), which is not held — Part III §3, PDF p. 31 Part II §7.2 2) · PDF pp. 29–30 |
| KR Rules for the Classification of Steel Ships, Part 12026 edition — Ch 3 Sec 1 for CSR ships | corrosion working along a free edge may take in under a quarter of the member: less than 25 % of the flange breadth, or — where the stiffener is a flat bar — less than 25 % of the web height the clause points at Pt 1 Ch 2 Fig 1.2.4 for the drawing — PDF p. 32 Pt 1 Ch 3 Sec 1, 105. 2 (2)(A) · PDF p. 134 | t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two; and the mean thickness taken right across the stiffener, over its flange breadth or its web height, must still reach the renewal figure set by CSR Ch 13, whichever applies the symbols are not repeated; the clause refers back to 105. 2 (1)(B) Pt 1 Ch 3 Sec 1, 105. 2 (2)(A) and (B) · PDF p. 134 | a plate edge at a manhole or lightening hole is allowed to sit under the rule minimum on two conditions. The thinned band must run inward from that edge over 20 % at most of the opening's smallest dimension, and never beyond 100 mm. A ragged edge may be trimmed, so long as the trimming enlarges the opening's largest dimension by 10 % at most and leaves the fresh edge at t_ren − 1 mm or thicker for ships not built under CSR, KR prints no edge corrosion criterion Pt 1 Ch 3 Sec 1, 105. 2 (2)(C)(a) and (b) · PDF p. 134 |
| PRSPublication 63/P for single side skin bulk carrier side frames; Part I, January 2026 for the rest | not published the term edge corrosion does not appear in the 16 pages; §2 runs renewal criteria, thickness measurement, reinforcing measures, weld throat thickness, pitting and grooving, and renewal of frames §2 Contents · PDF p. 3 | not published the term does not appear in the 127 pages of Part I either; the acceptance criteria clause names the Rules and UR S18, UR S21 and UR S21A and prints no local-corrosion figure §5.1.3.6 · PDF p. 44 | not published §5.1.3.6 · PDF p. 44 |
| INSB Rules and Regulations, Part IIssue 04 Rev.03, December 2024 — Ch 5 Sec 1 | corrosion working along a free edge may take in under a quarter of the member: less than 25 % of the flange breadth, or — where the stiffener is a flat bar — less than 25 % of the web height CSR ships. Edge corrosion is defined in the definitions of the same section — PDF p. 89 — and no figure is printed with the criterion §1.13.2.1 · PDF p. 96 | t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two; and the mean thickness taken right across the stiffener, over its flange breadth or its web height, must still reach the figure set by the IACS Common Structural Rules §1.13.2.1 and §1.13.2.2 · PDF p. 96 | a plate edge at a manhole or lightening hole is allowed to sit under the rule minimum on two conditions. The thinned band must run inward from that edge over 20 % at most of the opening's smallest dimension, and never beyond 100 mm. A ragged edge may be trimmed, so long as the trimming enlarges the opening's largest dimension by 10 % at most and leaves the fresh edge at t_ren − 1 mm or thicker §1.13.2.3 (a) and (b) · PDF p. 96 |
| ClassNK Guidance for Undergoing Class Maintenance Surveys2014 edition — Appendix 4-5 | older edition — 2014corrosion working along a free edge may take in under a quarter of the member: less than 25 % of the flange breadth, or — where the stiffener is a flat bar — less than 25 % of the web height CSR-T and CSR-B ships. No figure is printed with the criterion Appendix 4-5 §5 (2)(a) · PDF p. 137 | older edition — 2014t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 mm — the lesser of the two; and the mean thickness taken right across the stiffener, over its flange breadth or its web height, must still reach the figure set by Chapter 13 Part CSR-B or Section 12 Part CSR-T Appendix 4-5 §5 (2)(a) and (b) · PDF p. 137 | older edition — 2014a plate edge at a manhole or lightening hole is allowed to sit under the rule minimum on two conditions. The thinned band must run inward from that edge over 20 % at most of the opening's smallest dimension, and never beyond 100 mm. A ragged edge may be trimmed, so long as the trimming enlarges the opening's largest dimension by 10 % at most and leaves the fresh edge at t_ren − 1 mm or thicker for ships outside CSR the guidance prints no edge criterion Appendix 4-5 §5 (2)(c) i) and ii) · PDF p. 137 |
| RINA Part A Ch 2 App 21 July 2024 set — ships not built under CSR | older edition — 1 Jul 2024not published the term edge corrosion does not appear in the 26 pages. The isolated-area criterion names grooving of a plate or web and local severe corrosion as its subjects and does not name edges [4.3.4] a) · PDF p. 12 | older edition — 1 Jul 2024not published [4.3.4] a) · PDF p. 12 | older edition — 1 Jul 2024not published the CSR edge criteria sit in App 3 and are on the next row [4.3.4] a) · PDF p. 12 |
| RINA Part A Ch 2 App 31 July 2024 set — CSR bulk carriers and CSR double hull oil tankers | older edition — 1 Jul 2024corrosion working along a free edge may take in under a quarter of the member: less than 25 % of the flange breadth, or — where the stiffener is a flat bar — less than 25 % of the web height printed three times, once for single skin bulk carriers, once for double skin bulk carriers and once for double hull oil tankers; all three point at Sec 2, Fig 1 for the drawing [3.2.3] · PDF p. 9, [4.2.3] · PDF p. 15, and [5.2.3] · PDF pp. 19–20 | older edition — 1 Jul 2024t_m > 0,7 (t_as-built − t_vol add), or t_m > t_ren − 1 — the lesser of the two; and the mean thickness taken right across the stiffener, over its flange breadth or its web height, must still reach the figure set by CSR Chapter 13, or Section 12 for a double hull oil tanker under the older CSR a strict inequality where the IACS URs print greater-than-or-equal [3.2.3] · PDF p. 9, and [5.2.3] · PDF pp. 19–20 | older edition — 1 Jul 2024a plate edge at a manhole or lightening hole is allowed to sit under the rule minimum on two conditions. The thinned band must run inward from that edge over 20 % at most of the opening's smallest dimension, and never beyond 100 mm. A ragged edge may be trimmed, so long as the trimming enlarges the opening's largest dimension by 10 % at most and leaves the fresh edge at t_ren − 1 mm or thicker the single skin bulk carrier text at [3.2.3] runs the two conditions as prose without a) and b) lettering; the wording is the same [3.2.3] · PDF p. 9, [4.2.3] a) and b) · PDF p. 15, and [5.2.3] a) and b) · PDF p. 20 |
| DNV-CG-0182 Section 9Edition July 2022 — ships not built under CSR | older edition — Jul 2022flat bar deck longitudinals: the corrosion may take in under 25 % of the web height, measured down the corroded edge the clause is written for flat bar deck longitudinals; the CSR wording covers any stiffener flange as well Sec.9 [3.1.2] a) · PDF p. 30 | older edition — Jul 2022at the edge itself 1/3 t_as_built has to be left, and left well rounded; what remains of the rest of the longitudinal has to clear the minimum allowable of Sec.2 through Sec.7, whichever applies 1/3 of as-built at the edge is far below the 0.7 (t_as-built − t_vol add) of the CSR wording; the second condition, the average across the member, is what holds it Sec.9 [3.1.2] b) and c) · PDF p. 30 | older edition — Jul 2022a plate edge at a manhole or lightening hole is allowed to sit under the rule minimum on two conditions. The thinned band must run inward from that edge over 20 % at most of the opening's smallest dimension, and should stay inside 100 mm. A ragged edge may be trimmed, so long as the trimming enlarges the opening's largest dimension by 10 % at most no remaining-thickness figure is attached to the cropped-back edge here, where the CSR wording requires t_ren − 1 mm. High-shear areas, and any area with a cut-out beside it, call for special care. Where edge corrosion has gone too far the standard repair is cropping and renewing with inserts of the original scantling; a reinforcement ring on a lap joint, extra flanges, or closing the opening off with collar plates may also be considered — Sec.9 [3.2], PDF p. 30 Sec.9 [3.1.3] a) and b) · PDF p. 30 |
| DNV-CG-0182 Section 10Edition July 2022 — CSR oil tankers and bulk carriers | older edition — Jul 2022corrosion working along a free edge may take in under a quarter of the member: less than 25 % of the flange breadth, or — where the stiffener is a flat bar — less than 25 % of the web height Figure 2, Edge corrosion, is on PDF p. 34. The same guideline therefore carries two different edge rules — the 1/3 fraction of Sec.9 and this formula — and the CSR status of the ship decides which one is read Sec.10 [3.1] · PDF p. 33 | older edition — Jul 2022t_m ≥ 0.7 (t_as-built − t_vol add), or t_m ≥ t_ren − 1 — the lesser of the two [3.2] on the average across the stiffener reads, as printed, that the average measured thickness shall be less than what is defined in IACS CSR — the reverse of UR Z10.2 §8.3.2 and of every other text here. Read it as the IACS wording: not to be less than Sec.10 [3.1] · PDF p. 33 | older edition — Jul 2022a plate edge at a manhole or lightening hole is allowed to sit under the rule minimum on two conditions. The thinned band must run inward from that edge over 20 % at most of the opening's smallest dimension, and never beyond 100 mm. A ragged edge may be trimmed, so long as the trimming enlarges the opening's largest dimension by 10 % at most and leaves the fresh edge at t_ren − 1 mm or thicker Sec.10 [3.3] 1) and 2) · PDF p. 34 |
| LR Thickness Measurement and Close-up Survey Guidance, Part 1Ver 7.3, November 2016 — Ch 5 Sec 7 | older edition — Nov 2016 v7.3corrosion working along a free edge may take in under a quarter of the member: less than 25 % of the flange breadth, or — where the stiffener is a flat bar — less than 25 % of the web height printed under the heading CSR Tankers only, as the grooving criterion in the same clause is. An example figure sits on PDF p. 41 §1.5.7.6, Edge Corrosion · PDF p. 42 | older edition — Nov 2016 v7.3t_m ≥ 0.7 (t_as-built − t_own), or t_m ≥ t_renewal − 1 mm — the lesser of the two; and the mean thickness taken right across the stiffener, over its flange breadth or its web height, must still reach the renewal thickness for the general corrosion allowance t_own is this document's name for the owner's extra thickness §1.5.7.6 · PDF p. 42 | older edition — Nov 2016 v7.3a plate edge at a manhole or lightening hole is allowed to sit under the rule minimum on two conditions. The thinned band must run inward from that edge over 20 % at most of the opening's smallest dimension, and never beyond 100 mm. A ragged edge may be trimmed, so long as the trimming enlarges the opening's largest dimension by 10 % at most condition (b) stops at the 10 % and prints no remaining-thickness figure for the new edge, where UR Z10.2 §8.3.3 (b) requires t_ren − 1 mm §1.5.7.6 (a) and (b) · PDF p. 42 |
Editions read. Every value was read from the edition named on its source card, and the source card names the file held. Current at the date of verification and carrying no badge: IACS UR Z10.1 Rev.25, Z10.2 Rev.37, Z10.3 Rev.21, Z10.4 Rev.18 and Z10.5 Rev.20, all 2023 and in force for surveys commenced on or after 1 July 2024; IACS Rec 76 Rev.2 Corr.1 and Rec 96 Rev.2; ABS Part 7, July 2026; BV NR467 Part A R26, July 2026; KR Part 1, 2026; PRS Part I, January 2026; INSB Part I Issue 04 Rev.03, December 2024; CCS Ver 6.6, March 2025. Four documents carry an edition badge on every cell because a newer edition exists and is not held: RINA Part A Ch 2 App 2 and App 3, 1 July 2024 set, superseded by the January 2025 edition plus amendments in force 1 January 2026; DNV-CG-0182, Edition July 2022; ClassNK Guidance, 2014 edition; LR Thickness Measurement and Close-up Survey Guidance Part 1, Ver 7.3, November 2016. PRS Publication 63/P is a separate case: the source registry records it with year 2024, and the cover, the imprint page and every page footer of the file held print July 2008. The criteria are cited as the July 2008 text. Guidance, not requirement. Cells marked guidance come from IACS Recommendation 76 and Recommendation 96. A recommendation is not a unified requirement and carries no acceptance criteria; both are here because both are read on board, and because their silence on numbers is itself the answer. CSR carries none of these three criteria. The renewal chapter of the Common Structural Rules is general and acceptance criteria only, and the acceptance criteria are local corrosion against t_ren and global corrosion against the hull girder percentages. The words pitting and edge corrosion do not appear in the 812 pages; grooving appears once, in a newbuilding clause on protecting hatch openings against wire rope. The pitting, edge and grooving arithmetic for a CSR ship is printed in UR Z10.2 §8, UR Z10.4 §8 and UR Z10.5 §8, and CSR Pt 1 Ch 13 Sec 2 [2.1.3] points at those three URs by name. Each figure here is attributed to the document that prints it, not to CSR. What is referred to and not held. Three chains end outside the files on hand: CCS refers CSR ships out to CCS Rules Pt One Ch 5 Sec 1, 5.1.17 for all three defects; DNV refers single hull bulk carriers subject to ESP out to DNV-RU-SHIP Pt.7 Ch.1 Sec.3 [2.3.4]; PRS refers acceptance criteria out to the Rules and to UR S18, UR S21 and UR S21A. Those cells read "not published" against the clause that makes the referral, not against the document referred to.