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GB/T 3077 40CrNi2Mo vs AISI 4340

Close Alternative — 71.2% match based on chemical composition and mechanical property overlap.

GB/T 3077 40CrNi2Mo (GB/T 3077:2015) and AISI 4340 are both steel grades. Both fall under the Alloy Steel category. GB/T 3077 40CrNi2Mo is typically used for hot-rolled or forged structural alloy steel bars, while AISI 4340 is commonly used for aircraft parts, heavy duty gears, crankshafts, high tensile bolts. GB/T 3077 40CrNi2Mo is defined under Guobiao Standards (GB/T), originating from China, while AISI 4340 is defined under AISI, originating from United States.

As per chemical composition, GB/T 3077 40CrNi2Mo vs AISI 4340 is a 94.3% match. As per mechanical properties, the match is 25%. Combined, this makes them a close alternative overall at 71.2%.

Frequently Compared With GB/T 3077 40CrNi2Mo:
IS 1570 (Part 7) 10Mo6H UNI 11234 100Cr6 IS 4367 10Cr9Mo10 IS 4367 07Cr4Mo6 IS 1570 (Part 4) 07Cr4Mo6 NF A35-565 100C6 IS 1570 (Part 4) 103Cr4 IS 1570 (Part 4) 103Cr6 IS 1570 (Part 4) 105Cr5 IS 1570 (Part 4) 10Cr20Mo6 IS 1570 (Part 7) 10Cr36Mo10H EN 10028-2 10CrMo9-10
Match Breakdown
CHEMISTRY MATCH
94.3%
MECHANICAL MATCH
25%
OVERALL
71.2%
Specifications
Property GB/T 3077 40CrNi2Mo AISI 4340
Standard GB/T 3077:2015 AISI
Category Alloy Steel Alloy Steel
C (%) 0.38-0.43 0.38–0.43
Si (%) 0.17-0.37 0.15–0.35
Mn (%) 0.60-0.80 0.60–0.80
Cr (%) 0.70-0.90 0.70–0.90
Mo (%) 0.20-0.30 0.20–0.30
Ni (%) 1.65-2.00 1.65–2.00
P (%) <=0.030 Not specified
S (%) <=0.030 Not specified
Cu (%) <=0.30 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 GB/T 3077 40CrNi2Mo AISI 4340
Tensile Strength >=1050 MPa 1000–1200 MPa
Yield Strength >=980 MPa ≥830 MPa
Elongation >=12% ≥12%
Hardness <=269 HB 285–341 HB
Condition Quenched and tempered, test sample 25 mm; hardness is for bars delivered annealed or high temperature tempered Quenched & Tempered
Typical Applications
GB/T 3077 40CrNi2Mo
Hot-rolled or forged structural alloy steel bars
AISI 4340
Aircraft parts, heavy duty gears, crankshafts, high tensile bolts
Key Differences
Can GB/T 3077 40CrNi2Mo Be Substituted With AISI 4340?
GB/T 3077 40CrNi2Mo and AISI 4340 are a close alternative rather than a direct substitute. Some properties overlap well, but check the specific chemistry and mechanical rows above against your application's requirements before treating them as interchangeable.
Forms & Sizes Available on M-EX
GB/T 3077 40CrNi2Mo
No active listings currently.
AISI 4340
Round Bar → (3 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 5900–6800 mm (232.28–267.72 in)
On M-EX Right Now
GB/T 3077 40CrNi2Mo
0 active listings and RFQs →
AISI 4340
3 active listings and RFQs →
Frequently Asked Questions
What is the difference between GB/T 3077 40CrNi2Mo and AISI 4340?
GB/T 3077 40CrNi2Mo specifies P, S, Cu which are not specified for AISI 4340.
Can GB/T 3077 40CrNi2Mo be substituted with AISI 4340?
GB/T 3077 40CrNi2Mo and AISI 4340 are a close alternative rather than a direct substitute. Some properties overlap well, but check the specific chemistry and mechanical rows above against your application's requirements before treating them as interchangeable.