Close Alternative — 84.2% match
based on chemical composition and mechanical property overlap.
BS 970 EN57 (BS 970:1955) and BS 970 (Part 3) 431S29 (BS 970 (Part 3):1991) are both steel grades.
Both fall under the Stainless Steel category.
BS 970 EN57 is typically used for bars and billets for forging; forgings and drop-forgings; bars for machining; bright bars. suitable for tensile strength of 55 tons/sq in min., while BS 970 (Part 3) 431S29 is commonly used for bright cold finished bars (cold drawn, turned or precision ground) for general engineering purposes, in straight lengths; martensitic stainless steel (table 17).
BS 970 EN57 is defined under British Standards (BS), originating from United Kingdom, while BS 970 (Part 3) 431S29 is defined under British Standards (BS), originating from United Kingdom.
As per chemical composition, BS 970 EN57 vs BS 970 (Part 3) 431S29 is a 84.2% match.
Mechanical property data is not available for both grades, so this factor could not be scored.
Combined, this makes them a close alternative overall at 84.2%.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property
BS 970 EN57
BS 970 (Part 3) 431S29
Tensile Strength
≥849 MPa (55 tons/sq in, converted)
Not specified
Yield Strength
≥680 MPa (44 tons/sq in, converted)
Not specified
Elongation
≥15%
Not specified
Hardness
248 HB
Not specified
Condition
Hardened and tempered (ruling 6), ruling section 6 in (lowest-strength condition of the standard)
Not specified
Typical Applications
BS 970 EN57
Bars and billets for forging; forgings and drop-forgings; bars for machining; bright bars. Suitable for tensile strength of 55 tons/sq in min.
BS 970 (Part 3) 431S29
Bright cold finished bars (cold drawn, turned or precision ground) for general engineering purposes, in straight lengths; martensitic stainless steel (Table 17)
Can BS 970 EN57 Be Substituted With BS 970 (Part 3) 431S29?
BS 970 EN57 and BS 970 (Part 3) 431S29 are a close alternative rather than a direct substitute. Some properties overlap well, but check the specific chemistry and mechanical rows above against your application's requirements before treating them as interchangeable.
What is the difference between BS 970 EN57 and BS 970 (Part 3) 431S29?
Both grades share a similar composition profile; see the specification table above for the exact chemistry and mechanical property values.
Can BS 970 EN57 be substituted with BS 970 (Part 3) 431S29?
BS 970 EN57 and BS 970 (Part 3) 431S29 are a close alternative rather than a direct substitute. Some properties overlap well, but check the specific chemistry and mechanical rows above against your application's requirements before treating them as interchangeable.