Strong Match — 100% match
based on chemical composition and mechanical property overlap.
BS 970 (Part 3) 321S31 (BS 970 (Part 3):1991) and ASTM A959 347 (ASTM A959:2011) are both steel grades.
Both fall under the Stainless Steel category.
BS 970 (Part 3) 321S31 is typically 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), while ASTM A959 347 is commonly used for wrought stainless steel products; recommended composition limits for adoption by product standards (clause 1.1).
BS 970 (Part 3) 321S31 is defined under British Standards (BS), originating from United Kingdom, while ASTM A959 347 is defined under ASTM International, originating from United States.
As per chemical composition, BS 970 (Part 3) 321S31 vs ASTM A959 347 is a 100% 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 100%.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Typical Applications
BS 970 (Part 3) 321S31
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 347
Wrought stainless steel products; recommended composition limits for adoption by product standards (clause 1.1)
Can BS 970 (Part 3) 321S31 Be Substituted With ASTM A959 347?
BS 970 (Part 3) 321S31 and ASTM A959 347 overlap closely enough on chemistry and mechanical properties that ASTM A959 347 is often considered as a substitute for BS 970 (Part 3) 321S31 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 BS 970 (Part 3) 321S31 and ASTM A959 347?
Both grades share a similar composition profile; see the specification table above for the exact chemistry and mechanical property values.
Can BS 970 (Part 3) 321S31 be substituted with ASTM A959 347?
BS 970 (Part 3) 321S31 and ASTM A959 347 overlap closely enough on chemistry and mechanical properties that ASTM A959 347 is often considered as a substitute for BS 970 (Part 3) 321S31 in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.