US standard ASTM A240 and European standard EN 10088-2 cover the same category of product: corrosion-resistant stainless steel plate and strip. So correspondences like 304 ↔ 1.4301 and 316L ↔ 1.4404 are commonly used in the industry. But 'can correspond' does not mean 'completely equivalent.' Writing just the three characters '304' in a contract is the most dispute-prone approach.
One-Sentence Verdict
Mutual recognition is possible, but you must specify the governing standard + grade + condition. The correct way is '316L, ASTM A240' or '1.4404, EN 10088-2.' When only '316L' is written, once chemical composition or mechanical properties fall in the difference zone between the two standards, each party has its own justification.
Common Grade Cross-Reference
- 304 ↔ 1.4301; 304L ↔ 1.4307
- 316 ↔ 1.4401; 316L ↔ 1.4404
- 316Ti ↔ 1.4571 (commonly used 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 boundaries do not fully overlap (individual grades have different upper/lower limits for nickel/chromium and different ways of writing the carbon upper limit). If procurement accepts inspection according to one standard while the supplier produces according to the other, measured values may 'pass A but 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 table values are not entirely identical; elongation gauge length 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 item details (e.g., whether impact testing is mandatory, how surface quality grading 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 followed.
How to Write Purchase Orders to Avoid Losses
- State the material standard (A240 or EN 10088-2) clearly; do not write only the grade;
- State the delivery condition clearly (solution annealed/annealed, surface finish 2B/BA/No.1);
- State the certificate type clearly (EN 10204 3.1 or 3.2);
- When cross-standard mutual recognition is needed, specify in the contract 'which standard governs acceptance' — this one sentence can save an entire return process;
- Agree on thickness tolerances separately (A240 and EN 10088-2 have different tolerance tables; see the separate article 'Thickness Tolerances').
Common Pitfalls
- The drawing says '304,' but the delivered plate was produced by a domestic mill to GB/T 4237 — 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): different carbon content means different consequences for welded parts;
- Using '304' as a blanket term for both 304 and 304L, so where low carbon is actually needed, ordinary 304 is supplied;
- Attaching a cross-reference table directly as a contract annex without stating 'which standard governs acceptance.'
Tell us your target market and project requirements (US or European standard, whether a 3.2 certificate is needed, which tolerance table applies to thickness), and we will supply according to the corresponding standard and provide batch certificates — write the standard clearly, and you save a round of disputes later.
