Units and ordered dimensions
One inch is exactly 25.4 mm and one foot is 304.8 mm. Thus 1 inch × 4 feet × 8 feet converts to 25.4 × 1219.2 × 2438.4 mm. Confirm whether the enquiry describes finished blanks or mother plates and allow for kerf and edge preparation.
Acceptance limits
IACS W13 addresses thickness tolerances within its scope; length, width, flatness and positive thickness tolerance can come from the agreed dimensional standard. Do not label every ship plate tolerance as ±0.3 mm. Check the current society rule, measurement pattern and any zero-minus option before specifying numerical limits.
Inspection record
Record instrument calibration, measurement positions, edge condition and whether scale or coating affects the reading. Separate a thin original plate from in-service corrosion loss. Width and flatness claims require their own measuring method and reference length.
Information to record
- Exact product standard and edition; approved drawing or specification revision.
- Grade, dimensions, final condition and heat-to-piece traceability.
- Acceptance test, inspection document and responsible approving party.
W13 Rev.7 thickness reference
For W11/W16 plate within W13 scope (width ≥600 mm, thickness ≥5 mm), the nominal-thickness minus tolerance is 0.3 mm; the measured average must still meet nominal thickness. This is not a ±0.3 mm rule. Positive tolerance follows the agreed dimensional standard. Boiler and pressure-vessel plate are outside this rule’s scope. Check any approved alternative under W13.1.4 and the project requirements.
Frequently asked questions
Are all catalogue dimensions available in every grade?
No. Grade, thickness, width, delivery condition and mill approval constrain the available combinations. Confirm them on the quotation.
Sources and reference scope
- Procurement and editorial guidance — Cross-checked against product terminology and the cited material rules
Guidance describes checks to request. It is not a claim of available stock, certificates or completed project engineering. - 钢材产品简介 — Slides 3, 5–6, 15–19
Product forms, units and grade vocabulary; not proof of current stock or class certification. - IACS UR W13 Rev.7 (September 2021) — Scope; W13.3.2 and W13.4.2; alternate standard provision W13.1.4
Nominal minus tolerance and measured average are separate checks. Positive tolerance follows the agreed standard; confirm project scope and exceptions.