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AISI 4340 vs GB/T 3077 40CrNi2Mo

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

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

As per chemical composition, AISI 4340 vs GB/T 3077 40CrNi2Mo 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 AISI 4340:
NF A35-565 100C6 UNI 11234 100Cr6 GB/T 3077 12Cr2Ni4A GOST 4543 12HN3A IS 1570 (Part 4) 103Cr4 IS 1570 (Part 4) 105Cr5 IS 4367 07Cr4Mo6 IS 1570 (Part 4) 103Cr6 IS 1570 (Part 4) 10Cr20Mo6 IS 1570 (Part 7) 10Cr36Mo10H IS 1570 (Part 4) 07Cr4Mo6 IS 4367 10Cr9Mo10
Match Breakdown
CHEMISTRY MATCH
94.3%
MECHANICAL MATCH
25%
OVERALL
71.2%
Specifications
Property AISI 4340 GB/T 3077 40CrNi2Mo
Standard AISI GB/T 3077:2015
Category Alloy Steel Alloy Steel
C (%) 0.38–0.43 0.38-0.43
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
Si (%) 0.15–0.35 0.17-0.37
P (%) Not specified <=0.030
S (%) Not specified <=0.030
Cu (%) Not specified <=0.30
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property AISI 4340 GB/T 3077 40CrNi2Mo
Condition Quenched & Tempered Quenched and tempered, test sample 25 mm; hardness is for bars delivered annealed or high temperature tempered
Tensile Strength 1000–1200 MPa >=1050 MPa
Yield Strength ≥830 MPa >=980 MPa
Elongation ≥12% >=12%
Hardness 285–341 HB <=269 HB
Typical Applications
AISI 4340
Aircraft parts, heavy duty gears, crankshafts, high tensile bolts
GB/T 3077 40CrNi2Mo
Hot-rolled or forged structural alloy steel bars
Key Differences
Can AISI 4340 Be Substituted With GB/T 3077 40CrNi2Mo?
AISI 4340 and GB/T 3077 40CrNi2Mo 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
AISI 4340
Round Bar → (3 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 5900–6800 mm (232.28–267.72 in)
GB/T 3077 40CrNi2Mo
No active listings currently.
On M-EX Right Now
AISI 4340
3 active listings and RFQs →
GB/T 3077 40CrNi2Mo
0 active listings and RFQs →
Frequently Asked Questions
What is the difference between AISI 4340 and GB/T 3077 40CrNi2Mo?
GB/T 3077 40CrNi2Mo specifies P, S, Cu which are not specified for AISI 4340.
Can AISI 4340 be substituted with GB/T 3077 40CrNi2Mo?
AISI 4340 and GB/T 3077 40CrNi2Mo 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.