ASTM A240 (US standard) and EN 10088-2 (European standard) cover the same category of product: corrosion-resistant stainless steel plate and strip. So correspondences such as 304 ↔ 1.4301 and 316L ↔ 1.4404 are widely used in the industry. But 'can correspond' does not mean 'completely equivalent'. Writing just the three characters '304' in a contract is the wording most likely to lead to arguments.
One-sentence verdict
Cross-recognition is possible, but you must state the standard + grade + condition.The correct wording is '316L, ASTM A240' or '1.4404, EN 10088-2'. If you write only '316L', then once the chemical composition or mechanical properties fall in the difference zone between the two standards, each side will have its own justification.
Common grade cross-reference
- 304 ↔1.4301; 304L ↔1.4307
- 316 ↔1.4401; 316L ↔1.4404
- 316Ti ↔1.4571(common in Europe; the corresponding grade in A240 is 316Ti)
- 321 ↔1.4541
- 2205 duplex steel ↔1.4462
- 310S ↔1.4845
Three details that actually differ
① Chemical composition ranges.Broadly consistent, but the boundaries do not fully overlap (for some grades the upper and lower limits for nickel/chromium and the way the carbon upper limit is written differ). If the buyer accepts only according to one standard while the supplier produces according to the other, the measured values may 'pass A, fail B'.
② Mechanical property units and values.US standards use ksi, European standards use MPa. The definition of yield strength (0.2% offset) is the same, but the table values are not entirely identical; the gauge length for elongation may also differ. Unify units and test methods before comparing data.
③ Inspection items and certificates.Both require chemical composition and mechanical properties per batch, but the detailed items (e.g. whether impact testing is mandatory, how surface quality classification is written) differ. Under the EN system, EN 10204 3.1/3.2 is often cited as the certificate type; under the US system, A240 annexes or customer specifications are often used.
How to write purchase orders so you don't lose out
- State thematerial standard(A240 or EN 10088-2), not just the grade;
- State thedelivery condition(solution annealed/annealed, surface finish 2B/BA/No.1);
- State thecertificate type(EN 10204 3.1 or 3.2);
- When cross-standard recognition is needed, specify in the contract 'which standard is used for acceptance' — this sentence can save an entire return process;
- Agree thickness tolerances separately (the tolerance tables of A240 and EN 10088-2 differ; see the separate article 'Thickness Tolerances').
Common pitfalls
- The drawing says '304', but the delivered plate is produced by a domestic mill to GB/T 4237 — the chemical composition may fully comply, but when the customer re-inspects to A240, impact or tolerances do not match;
- Mixing up 1.4404 and 1.4401 (316 and 316L): the carbon content differs, and the consequences for welded parts differ;
- Using '304' as a blanket term for both 304 and 304L, so where low carbon is actually required, ordinary 304 is supplied;
- Attaching the cross-reference table directly as a contract annex without stating 'which standard is used for acceptance'.
Tell us your target market and project requirements (US or European standard, whether a 3.2 certificate is needed, which tolerance table applies), and we will supply to the corresponding standard and provide batch certificates — write the standard clearly, and you save a round of arguments later.
