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ASTM A959 309Cb vs ASTM A240/A240M S30940

Strong Match — 93.3% match based on chemical composition and mechanical property overlap.

ASTM A959 309Cb (ASTM A959:2011) and ASTM A240/A240M S30940 (ASTM A240/A240M:2025) are both steel grades. Both fall under the Stainless Steel category. ASTM A959 309Cb is typically used for wrought stainless steel products; recommended composition limits for adoption by product standards (clause 1.1), while ASTM A240/A240M S30940 is commonly used for pressure vessels and general applications (plate, sheet and strip). ASTM A959 309Cb is defined under ASTM International, originating from United States, while ASTM A240/A240M S30940 is defined under ASTM International, originating from United States.

As per chemical composition, ASTM A959 309Cb vs ASTM A240/A240M S30940 is a 93.3% 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 93.3%.

Frequently Compared With ASTM A959 309Cb:
GOST 5632 08X18H10 EN 10088-1 1.4006 IS 1570 (Part 7) 12Cr13H EN 10088-1 1.4401 IS 1570 (Part 7) 12Cr12MoVH GB/T 3280 06Cr19Ni10 EN 10088-1 1.4301 GOST 5632 06Kh23N28 EN 10088-1 1.4845 IS 1570 (Part 7) 11Cr17Ni13W3TiH IS 1570 (Part 7) 12Cr12MoH ASTM A959 .-
Match Breakdown
CHEMISTRY MATCH
93.3%
MECHANICAL MATCH
No shared data
OVERALL
93.3%
Specifications
Property ASTM A959 309Cb ASTM A240/A240M S30940
Standard ASTM A959:2011 ASTM A240/A240M:2025
Category Stainless Steel Stainless Steel
C (%) <=0.08 <=0.08
Cr (%) 22.0-24.0 22.0-24.0
Mn (%) <=2.00 <=2.00
Ni (%) 12.0-16.0 12.0-16.0
P (%) <=0.045 <=0.045
S (%) <=0.030 <=0.030
Si (%) <=1.00 <=0.75
Nb (%) Not specified <=1.10
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property ASTM A959 309Cb ASTM A240/A240M S30940
Tensile Strength Not specified >=515 MPa
Yield Strength Not specified >=205 MPa
Elongation Not specified >=40%
Hardness Not specified <=217 HB
Condition Not specified Plate, sheet and strip; yield by 0.2 percent offset
Typical Applications
ASTM A959 309Cb
Wrought stainless steel products; recommended composition limits for adoption by product standards (clause 1.1)
ASTM A240/A240M S30940
Pressure vessels and general applications (plate, sheet and strip)
Key Differences
Can ASTM A959 309Cb Be Substituted With ASTM A240/A240M S30940?
ASTM A959 309Cb and ASTM A240/A240M S30940 overlap closely enough on chemistry and mechanical properties that ASTM A240/A240M S30940 is often considered as a substitute for ASTM A959 309Cb in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.
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ASTM A959 309Cb
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ASTM A240/A240M S30940
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Frequently Asked Questions
What is the difference between ASTM A959 309Cb and ASTM A240/A240M S30940?
ASTM A240/A240M S30940 specifies Nb which is not specified for ASTM A959 309Cb.
Can ASTM A959 309Cb be substituted with ASTM A240/A240M S30940?
ASTM A959 309Cb and ASTM A240/A240M S30940 overlap closely enough on chemistry and mechanical properties that ASTM A240/A240M S30940 is often considered as a substitute for ASTM A959 309Cb in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.