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BS 970 EN30A vs GOST 4543 12HN3A

Minimal Match — 47% match based on chemical composition and mechanical property overlap.

BS 970 EN30A (BS 970:1955) and GOST 4543 12HN3A (GOST 4543-2016) are both steel grades. Both fall under the Alloy Steel category. BS 970 EN30A is typically used for used for gears, aircraft components, transmission shafts, heavy-duty pinions, crankshafts, and high-strength fasteners., while GOST 4543 12HN3A is commonly used for used for gears, pinions, crankshafts, aircraft parts, and transmission components.. BS 970 EN30A is defined under British Standards (BS) (United Kingdom).

As per chemical composition, BS 970 EN30A vs GOST 4543 12HN3A is a 70.5% match. As per mechanical properties, the match is 0%. Combined, this makes them a minimal match overall at 47%.

Frequently Compared With BS 970 EN30A:
UNI 11234 100Cr6 NF A35-565 100C6 GB/T 3077 12Cr2Ni4A IS 1570 (Part 4) 103Cr6 IS 4367 07Cr4Mo6 IS 1570 (Part 4) 07Cr4Mo6 IS 1570 (Part 7) 10Cr36Mo10H IS 1570 (Part 4) 103Cr4 IS 4367 10Cr9Mo10 IS 1570 (Part 4) 105Cr5 IS 1570 (Part 4) 10Cr20Mo6 EN 10028-2 10CrMo9-10
Match Breakdown
CHEMISTRY MATCH
70.5%
MECHANICAL MATCH
0%
OVERALL
47%
Specifications
Property BS 970 EN30A GOST 4543 12HN3A
Standard BS 970:1955 GOST 4543-2016
Category Alloy Steel Alloy Steel
C (%) 0.26-0.34 0.09-0.16
Si (%) 0.10-0.35 0.17-0.37
Mn (%) 0.40-0.60 0.3-0.6
Ni (%) 3.90-4.30 2.75-3.15
Cr (%) 1.10-1.40 0.6-0.9
S (%) <=0.050 Not specified
P (%) <=0.050 Not specified
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 EN30A GOST 4543 12HN3A
Tensile Strength ≥1544 MPa (100 tons/sq in, converted) 850-1050 MPa
Yield Strength ≥1313 MPa (85 tons/sq in, converted) 685 MPa min
Elongation ≥10% 11% min
Hardness 444 HB 58-62 HRC (case)
Condition Air hardened and tempered (lowest-strength condition of the standard) Not specified
Typical Applications
BS 970 EN30A
Used for gears, aircraft components, transmission shafts, heavy-duty pinions, crankshafts, and high-strength fasteners.
GOST 4543 12HN3A
Used for gears, pinions, crankshafts, aircraft parts, and transmission components.
Key Differences
Can BS 970 EN30A Be Substituted With GOST 4543 12HN3A?
BS 970 EN30A 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 EN30A
Round Bar → (2 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 6400–6600 mm (251.97–259.84 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 EN30A
2 active listings and RFQs →
GOST 4543 12HN3A
2 active listings and RFQs →
Frequently Asked Questions
What is the difference between BS 970 EN30A and GOST 4543 12HN3A?
BS 970 EN30A specifies S, P which are not specified for GOST 4543 12HN3A.
Can BS 970 EN30A be substituted with GOST 4543 12HN3A?
BS 970 EN30A 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.