Related Material — 65% match
based on chemical composition and mechanical property overlap.
GB/T 699 15 (GB/T 699:2015) and BS 970 (Part 1) 635M15 (BS 970 (Part 1):1983) are both steel grades.
GB/T 699 15 is classified under Carbon Steel, while BS 970 (Part 1) 635M15 is classified under Alloy Steel — a different category, which is worth noting alongside the chemistry match below.
GB/T 699 15 is typically used for hot-rolled or forged quality carbon structural steel bars up to 250 mm, while BS 970 (Part 1) 635M15 is commonly used for case hardening steel for mechanical and allied engineering purposes (table 11 mechanical properties)..
GB/T 699 15 is defined under Guobiao Standards (GB/T), originating from China, while BS 970 (Part 1) 635M15 is defined under British Standards (BS), originating from United Kingdom.
As per chemical composition, GB/T 699 15 vs BS 970 (Part 1) 635M15 is a 69.3% match.
Mechanical property data is not available for both grades, so this factor could not be scored.
Combined, this makes them a related material overall at 65%.
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 15
BS 970 (Part 1) 635M15
Tensile Strength
>=375 MPa
Not specified
Yield Strength
>=225 MPa
Not specified
Elongation
>=27%
Not specified
Hardness
<=143 HB (as delivered, not heat treated)
Not specified
Condition
Normalized 25 mm sample blank, bars up to 80 mm; hardness for delivery state
Not specified
Typical Applications
GB/T 699 15
Hot-rolled or forged quality carbon structural steel bars up to 250 mm
BS 970 (Part 1) 635M15
Case hardening steel for mechanical and allied engineering purposes (Table 11 mechanical properties).
Key Differences
Different category: GB/T 699 15 is Carbon Steel, BS 970 (Part 1) 635M15 is Alloy Steel.
GB/T 699 15 specifies Si, Cu which are not specified for BS 970 (Part 1) 635M15.
Can GB/T 699 15 Be Substituted With BS 970 (Part 1) 635M15?
GB/T 699 15 and BS 970 (Part 1) 635M15 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 15 and BS 970 (Part 1) 635M15?
Different category: GB/T 699 15 is Carbon Steel, BS 970 (Part 1) 635M15 is Alloy Steel. GB/T 699 15 specifies Si, Cu which are not specified for BS 970 (Part 1) 635M15.
Can GB/T 699 15 be substituted with BS 970 (Part 1) 635M15?
GB/T 699 15 and BS 970 (Part 1) 635M15 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.