Strong Match — 98.6% match
based on chemical composition and mechanical property overlap.
ASTM A240/A240M S30908 (ASTM A240/A240M:2025) and ASTM A959 309S (ASTM A959:2011) are both steel grades.
Both fall under the Stainless Steel category.
ASTM A240/A240M S30908 is typically used for pressure vessels and general applications (plate, sheet and strip), while ASTM A959 309S is commonly used for wrought stainless steel products; recommended composition limits for adoption by product standards (clause 1.1).
ASTM A240/A240M S30908 is defined under ASTM International, originating from United States, while ASTM A959 309S is defined under ASTM International, originating from United States.
As per chemical composition, ASTM A240/A240M S30908 vs ASTM A959 309S is a 98.6% 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 98.6%.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property
ASTM A240/A240M S30908
ASTM A959 309S
Tensile Strength
>=515 MPa
Not specified
Yield Strength
>=205 MPa
Not specified
Elongation
>=40%
Not specified
Hardness
<=217 HB
Not specified
Condition
Plate, sheet and strip; yield by 0.2 percent offset
Not specified
Typical Applications
ASTM A240/A240M S30908
Pressure vessels and general applications (plate, sheet and strip)
ASTM A959 309S
Wrought stainless steel products; recommended composition limits for adoption by product standards (clause 1.1)
Can ASTM A240/A240M S30908 Be Substituted With ASTM A959 309S?
ASTM A240/A240M S30908 and ASTM A959 309S overlap closely enough on chemistry and mechanical properties that ASTM A959 309S is often considered as a substitute for ASTM A240/A240M S30908 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 A240/A240M S30908 and ASTM A959 309S?
Both grades share a similar composition profile; see the specification table above for the exact chemistry and mechanical property values.
Can ASTM A240/A240M S30908 be substituted with ASTM A959 309S?
ASTM A240/A240M S30908 and ASTM A959 309S overlap closely enough on chemistry and mechanical properties that ASTM A959 309S is often considered as a substitute for ASTM A240/A240M S30908 in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.