Close Alternative — 83.8% match
based on chemical composition and mechanical property overlap.
BS 970 EN31 (BS 970:1955) and BS 970 (Part 1) 535A99 (BS 970 (Part 1):1983) are both steel grades.
Both fall under the Alloy Steel category.
BS 970 EN31 is typically used for ball and roller bearings, gauges, dies, while BS 970 (Part 1) 535A99 is commonly used for used for aircraft fittings, gears, high-strength shafts, crankshafts, heavy-duty fasteners, and transmission parts..
BS 970 EN31 is defined under British Standards (BS), originating from United Kingdom, while BS 970 (Part 1) 535A99 is defined under British Standards (BS), originating from United Kingdom.
As per chemical composition, BS 970 EN31 vs BS 970 (Part 1) 535A99 is a 83.8% 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 83.8%.
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 EN31
BS 970 (Part 1) 535A99
Hardness (HB)
≤229 (softened)
Not specified
Typical Applications
BS 970 EN31
Ball and roller bearings, gauges, dies
BS 970 (Part 1) 535A99
Used for aircraft fittings, gears, high-strength shafts, crankshafts, heavy-duty fasteners, and transmission parts.
Key Differences
BS 970 EN31 specifies Si which is not specified for BS 970 (Part 1) 535A99.
Can BS 970 EN31 Be Substituted With BS 970 (Part 1) 535A99?
BS 970 EN31 and BS 970 (Part 1) 535A99 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 EN31 and BS 970 (Part 1) 535A99?
BS 970 EN31 specifies Si which is not specified for BS 970 (Part 1) 535A99.
Can BS 970 EN31 be substituted with BS 970 (Part 1) 535A99?
BS 970 EN31 and BS 970 (Part 1) 535A99 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.