Minimal Match — 35% match
based on chemical composition and mechanical property overlap.
GB/T 699 40 (GB/T 699:2015) and BS 970 (Part 1) 055M15 (BS 970 (Part 1):1991) are both steel grades.
Both fall under the Carbon Steel category.
GB/T 699 40 is typically used for used for gears, shafts, axles, crankshafts, couplings, and machine spindles., while BS 970 (Part 1) 055M15 is commonly used for as-rolled, or as-rolled and softened, steel (section two).
GB/T 699 40 is defined under Guobiao Standards (GB/T), originating from China, while BS 970 (Part 1) 055M15 is defined under British Standards (BS), originating from United Kingdom.
As per chemical composition, GB/T 699 40 vs BS 970 (Part 1) 055M15 is a 64.1% match.
As per mechanical properties, the match is 0%.
Combined, this makes them a minimal match overall at 35%.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property
GB/T 699 40
BS 970 (Part 1) 055M15
Tensile Strength
>=570 MPa
310 MPa min
Yield Strength
>=335 MPa
Not specified
Elongation
>=19%
25 % min
Hardness
<=217 HB (as delivered, not heat treated)
121 HB min
Condition
Normalized 25 mm sample blank, bars up to 80 mm; hardness for delivery state
As-rolled
Typical Applications
GB/T 699 40
Used for gears, shafts, axles, crankshafts, couplings, and machine spindles.
BS 970 (Part 1) 055M15
As-rolled, or as-rolled and softened, steel (section two)
Key Differences
GB/T 699 40 specifies Si, P, S, Cr which are not specified for BS 970 (Part 1) 055M15.
Can GB/T 699 40 Be Substituted With BS 970 (Part 1) 055M15?
GB/T 699 40 and BS 970 (Part 1) 055M15 share some compositional similarity but differ enough that substitution should not be assumed. Review the differences above carefully, and consult the applicable standard or a metallurgist before using one in place of the other.
What is the difference between GB/T 699 40 and BS 970 (Part 1) 055M15?
GB/T 699 40 specifies Si, P, S, Cr which are not specified for BS 970 (Part 1) 055M15.
Can GB/T 699 40 be substituted with BS 970 (Part 1) 055M15?
GB/T 699 40 and BS 970 (Part 1) 055M15 share some compositional similarity but differ enough that substitution should not be assumed. Review the differences above carefully, and consult the applicable standard or a metallurgist before using one in place of the other.