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JIS G4103 SNCM439 vs GB/T 3077 40CrNiMo

Close Alternative — 75.9% match based on chemical composition and mechanical property overlap.

JIS G4103 SNCM439 (JIS G4103:1979) and GB/T 3077 40CrNiMo (GB/T 3077:2015) are both steel grades. Both fall under the Alloy Steel category. JIS G4103 SNCM439 is typically used for crankshafts, gears, heavy duty shafts, aircraft components, while GB/T 3077 40CrNiMo is commonly used for hot-rolled or forged structural alloy steel bars. JIS G4103 SNCM439 is defined under Japanese Industrial Standards (JIS), originating from Japan, while GB/T 3077 40CrNiMo is defined under Guobiao Standards (GB/T), originating from China.

As per chemical composition, JIS G4103 SNCM439 vs GB/T 3077 40CrNiMo is a 76.3% match. As per mechanical properties, the match is 75%. Combined, this makes them a close alternative overall at 75.9%.

Frequently Compared With JIS G4103 SNCM439:
GOST 4543 12HN3A NF A35-565 100C6 UNI 11234 100Cr6 GB/T 3077 12Cr2Ni4A IS 1570 (Part 4) 07Cr4Mo6 IS 4367 07Cr4Mo6 IS 1570 (Part 4) 103Cr4 IS 1570 (Part 4) 10Cr20Mo6 IS 1570 (Part 4) 105Cr5 IS 1570 (Part 4) 103Cr6 IS 1570 (Part 7) 10Cr36Mo10H IS 4367 10Cr9Mo10
Match Breakdown
CHEMISTRY MATCH
76.3%
MECHANICAL MATCH
75%
OVERALL
75.9%
Specifications
Property JIS G4103 SNCM439 GB/T 3077 40CrNiMo
Standard JIS G4103:1979 GB/T 3077:2015
Category Alloy Steel Alloy Steel
C (%) 0.36–0.43 0.37-0.44
Si (%) 0.15–0.35 0.17-0.37
Mn (%) 0.60–0.90 0.50-0.80
Cr (%) 0.60–1.00 0.60-0.90
Mo (%) 0.15–0.30 0.15-0.25
Ni (%) 1.60–2.00 1.25-1.65
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 JIS G4103 SNCM439 GB/T 3077 40CrNiMo
Tensile Strength ≥980 MPa >=980 MPa
Yield Strength ≥835 MPa >=835 MPa
Elongation ≥12% >=12%
Hardness 293–352 HB <=269 HB
Condition Not specified Quenched and tempered, test sample 25 mm; hardness is for bars delivered annealed or high temperature tempered
Typical Applications
JIS G4103 SNCM439
Crankshafts, gears, heavy duty shafts, aircraft components
GB/T 3077 40CrNiMo
Hot-rolled or forged structural alloy steel bars
Key Differences
Can JIS G4103 SNCM439 Be Substituted With GB/T 3077 40CrNiMo?
JIS G4103 SNCM439 and GB/T 3077 40CrNiMo 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
JIS G4103 SNCM439
Round Bar → (3 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 4900–5800 mm (192.91–228.35 in)
GB/T 3077 40CrNiMo
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On M-EX Right Now
JIS G4103 SNCM439
3 active listings and RFQs →
GB/T 3077 40CrNiMo
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Frequently Asked Questions
What is the difference between JIS G4103 SNCM439 and GB/T 3077 40CrNiMo?
GB/T 3077 40CrNiMo specifies P, S, Cu which are not specified for JIS G4103 SNCM439.
Can JIS G4103 SNCM439 be substituted with GB/T 3077 40CrNiMo?
JIS G4103 SNCM439 and GB/T 3077 40CrNiMo 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.