Strong Match — 93.6% match
based on chemical composition and mechanical property overlap.
ASTM A959 303 (ASTM A959:2011) and BS 970 (Part 3) 303S31 (BS 970 (Part 3):1991) are both steel grades.
Both fall under the Stainless Steel category.
ASTM A959 303 is typically used for wrought stainless steel products; recommended composition limits for adoption by product standards (clause 1.1), while BS 970 (Part 3) 303S31 is commonly used for bright cold finished bars (cold drawn, turned or precision ground) for general engineering purposes, in straight lengths; austenitic stainless and heat resisting steel (table 18).
ASTM A959 303 is defined under ASTM International, originating from United States, while BS 970 (Part 3) 303S31 is defined under British Standards (BS), originating from United Kingdom.
As per chemical composition, ASTM A959 303 vs BS 970 (Part 3) 303S31 is a 93.6% match.
Mechanical property data is not available for both grades, so this factor could not be scored.
Combined, this makes them a strong match overall at 93.6%.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Typical Applications
ASTM A959 303
Wrought stainless steel products; recommended composition limits for adoption by product standards (clause 1.1)
BS 970 (Part 3) 303S31
Bright cold finished bars (cold drawn, turned or precision ground) for general engineering purposes, in straight lengths; austenitic stainless and heat resisting steel (Table 18)
Can ASTM A959 303 Be Substituted With BS 970 (Part 3) 303S31?
ASTM A959 303 and BS 970 (Part 3) 303S31 overlap closely enough on chemistry and mechanical properties that BS 970 (Part 3) 303S31 is often considered as a substitute for ASTM A959 303 in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.
What is the difference between ASTM A959 303 and BS 970 (Part 3) 303S31?
Both grades share a similar composition profile; see the specification table above for the exact chemistry and mechanical property values.
Can ASTM A959 303 be substituted with BS 970 (Part 3) 303S31?
ASTM A959 303 and BS 970 (Part 3) 303S31 overlap closely enough on chemistry and mechanical properties that BS 970 (Part 3) 303S31 is often considered as a substitute for ASTM A959 303 in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.