Calculate consistently
With all dimensions in millimetres, mass in kg = thickness × width × length × 0.00000785. A 20 × 2000 × 6000 mm plate has a theoretical mass of 1,884 kg. Multiply by plate count for a line-item total; tonnes equal kilograms divided by 1,000.
Build a useful cutting allowance
Separate net component mass, nested blank mass and purchased mother-plate mass. Kerf, edge crop, weld preparations and remnant ownership affect yield. Do not add an unexplained percentage to the invoice weight; agree the commercial basis.
Receiving checks
Compare theoretical mass with the delivery note, weighbridge result and specified tolerance. For stainless steel or nickel alloys use the relevant density rather than the carbon-steel factor. A density assumption cannot prove chemistry or identify a grade.
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.
Frequently asked questions
Is theoretical weight the payable weight?
Only if the order says so. Agree actual or theoretical billing and the treatment of tolerances before purchase.
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.