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BS 970 EN18 vs GOST 4543 12HN3A

Minimal Match — 35% match based on chemical composition and mechanical property overlap.

BS 970 EN18 (BS 970:1955) and GOST 4543 12HN3A (GOST 4543-2016) are both steel grades. Both fall under the Alloy Steel category. BS 970 EN18 is typically used for gears, shafts, high tensile fasteners, while GOST 4543 12HN3A is commonly used for used for gears, pinions, crankshafts, aircraft parts, and transmission components.. BS 970 EN18 is defined under British Standards (BS) (United Kingdom).

As per chemical composition, BS 970 EN18 vs GOST 4543 12HN3A is a 67.4% match. As per mechanical properties, the match is 0%. Combined, this makes them a minimal match overall at 35%.

Frequently Compared With BS 970 EN18:
UNI 11234 100Cr6 GB/T 3077 12Cr2Ni4A NF A35-565 100C6 IS 1570 (Part 4) 07Cr4Mo6 IS 1570 (Part 4) 103Cr4 IS 1570 (Part 4) 10Cr20Mo6 IS 4367 07Cr4Mo6 IS 1570 (Part 4) 103Cr6 IS 1570 (Part 4) 105Cr5 IS 1570 (Part 7) 10Cr36Mo10H IS 4367 10Cr9Mo10 EN 10028-2 10CrMo9-10
Match Breakdown
CHEMISTRY MATCH
67.4%
MECHANICAL MATCH
0%
OVERALL
35%
Specifications
Property BS 970 EN18 GOST 4543 12HN3A
Standard BS 970:1955 GOST 4543-2016
Category Alloy Steel Alloy Steel
C (%) 0.35-0.45 0.09-0.16
Si (%) 0.10-0.35 0.17-0.37
Mn (%) 0.60-0.95 0.3-0.6
Cr (%) 0.85-1.15 0.6-0.9
S (%) <=0.050 Not specified
P (%) <=0.050 Not specified
Ni (%) Not specified 2.75-3.15
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 EN18 GOST 4543 12HN3A
Tensile Strength ≥695 MPa (45 tons/sq in, converted) 850-1050 MPa
Yield Strength ≥525 MPa (34 tons/sq in, converted) 685 MPa min
Elongation ≥22% 11% min
Hardness 201-255 HB 58-62 HRC (case)
Condition Hardened and tempered R, ruling section 4 in (lowest-strength condition of the standard) Not specified
Typical Applications
BS 970 EN18
Gears, shafts, high tensile fasteners
GOST 4543 12HN3A
Used for gears, pinions, crankshafts, aircraft parts, and transmission components.
Key Differences
Can BS 970 EN18 Be Substituted With GOST 4543 12HN3A?
BS 970 EN18 and GOST 4543 12HN3A 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.
Forms & Sizes Available on M-EX
BS 970 EN18
Round Bar → (3 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 5000–6800 mm (196.85–267.72 in)
Hex Bar → (3 listings)
Across Flats: 50–50 mm (1.97–1.97 in)
Length: 2500–2900 mm (98.43–114.17 in)
GOST 4543 12HN3A
Round Bar → (2 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 5600–6600 mm (220.47–259.84 in)
On M-EX Right Now
BS 970 EN18
6 active listings and RFQs →
GOST 4543 12HN3A
2 active listings and RFQs →
Frequently Asked Questions
What is the difference between BS 970 EN18 and GOST 4543 12HN3A?
BS 970 EN18 specifies S, P which are not specified for GOST 4543 12HN3A. GOST 4543 12HN3A specifies Ni which is not specified for BS 970 EN18.
Can BS 970 EN18 be substituted with GOST 4543 12HN3A?
BS 970 EN18 and GOST 4543 12HN3A 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.