Minimal Match — 35% match
based on chemical composition and mechanical property overlap.
BS 4659 BH21 (BS 4659:1989) and GB/T 1299 4Cr5MoSiV1 (GB/T 1299-2014) are both steel grades.
Both fall under the Tool & Die Steels category.
BS 4659 BH21 is typically used for hot extrusion dies, brass/bronze forging dies, while GB/T 1299 4Cr5MoSiV1 is commonly used for die casting dies, forging dies, extrusion tools.
BS 4659 BH21 is defined under British Standards (BS), originating from United Kingdom, while GB/T 1299 4Cr5MoSiV1 is defined under Guobiao Standards (GB/T), originating from China.
As per chemical composition, BS 4659 BH21 vs GB/T 1299 4Cr5MoSiV1 is a 56.1% 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
BS 4659 BH21
GB/T 1299 4Cr5MoSiV1
Hardness HRC (hardened)
36–54
42–54
Hardness HB (annealed)
≤229
≤235
Typical Applications
BS 4659 BH21
Hot extrusion dies, brass/bronze forging dies
GB/T 1299 4Cr5MoSiV1
Die casting dies, forging dies, extrusion tools
Key Differences
BS 4659 BH21 specifies W which is not specified for GB/T 1299 4Cr5MoSiV1.
GB/T 1299 4Cr5MoSiV1 specifies Si, Mo which are not specified for BS 4659 BH21.
Can BS 4659 BH21 Be Substituted With GB/T 1299 4Cr5MoSiV1?
BS 4659 BH21 and GB/T 1299 4Cr5MoSiV1 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 BS 4659 BH21 and GB/T 1299 4Cr5MoSiV1?
BS 4659 BH21 specifies W which is not specified for GB/T 1299 4Cr5MoSiV1. GB/T 1299 4Cr5MoSiV1 specifies Si, Mo which are not specified for BS 4659 BH21.
Can BS 4659 BH21 be substituted with GB/T 1299 4Cr5MoSiV1?
BS 4659 BH21 and GB/T 1299 4Cr5MoSiV1 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.