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GB/T 3077 20CrMnMo vs SAE J404 4120

Close Alternative — 77.3% match based on chemical composition and mechanical property overlap.

GB/T 3077 20CrMnMo (GB/T 3077:2015) and SAE J404 4120 (SAE J404:2009) are both steel grades. Both fall under the Alloy Steel category. GB/T 3077 20CrMnMo is typically used for hot-rolled or forged structural alloy steel bars, while SAE J404 4120 is commonly used for used for gears, crankshafts, studs, pins, machinery parts, and transmission components.. GB/T 3077 20CrMnMo is defined under Guobiao Standards (GB/T), originating from China, while SAE J404 4120 is defined under SAE International, originating from United States.

As per chemical composition, GB/T 3077 20CrMnMo vs SAE J404 4120 is a 77.3% match. Mechanical property data is not available for both grades, so this factor could not be scored. Combined, this makes them a close alternative overall at 77.3%.

Frequently Compared With GB/T 3077 20CrMnMo:
IS 1570 (Part 7) 10Mo6H UNI 11234 100Cr6 IS 1570 (Part 4) 103Cr4 IS 1570 (Part 4) 10Cr20Mo6 IS 1570 (Part 7) 10Cr36Mo10H IS 4367 10Cr9Mo10 IS 1570 (Part 4) 10Mo6 IS 4367 07Cr4Mo6 IS 1570 (Part 4) 07Cr4Mo6 NF A35-565 100C6 IS 1570 (Part 4) 103Cr6 IS 1570 (Part 4) 105Cr5
Match Breakdown
CHEMISTRY MATCH
77.3%
MECHANICAL MATCH
No shared data
OVERALL
77.3%
Specifications
Property GB/T 3077 20CrMnMo SAE J404 4120
Standard GB/T 3077:2015 SAE J404:2009
Category Alloy Steel Alloy Steel
C (%) 0.17-0.23 0.18-0.23
Si (%) 0.17-0.37 0.15-0.35
Mn (%) 0.90-1.20 0.90-1.20
Cr (%) 1.10-1.40 0.40-0.60
Mo (%) 0.20-0.30 0.13-0.20
P (%) <=0.030 <=0.030
S (%) <=0.030 <=0.040
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 20CrMnMo SAE J404 4120
Tensile Strength >=1180 MPa Not specified
Yield Strength >=885 MPa Not specified
Elongation >=10% Not specified
Hardness <=217 HB Not specified
Condition Quenched and tempered, test sample 15 mm; hardness is for bars delivered annealed or high temperature tempered Not specified
Typical Applications
GB/T 3077 20CrMnMo
Hot-rolled or forged structural alloy steel bars
SAE J404 4120
Used for gears, crankshafts, studs, pins, machinery parts, and transmission components.
Key Differences
Can GB/T 3077 20CrMnMo Be Substituted With SAE J404 4120?
GB/T 3077 20CrMnMo and SAE J404 4120 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 20CrMnMo
No active listings currently.
SAE J404 4120
Round Bar → (2 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 5800–6100 mm (228.35–240.16 in)
On M-EX Right Now
GB/T 3077 20CrMnMo
0 active listings and RFQs →
SAE J404 4120
2 active listings and RFQs →
Frequently Asked Questions
What is the difference between GB/T 3077 20CrMnMo and SAE J404 4120?
GB/T 3077 20CrMnMo specifies Cu which is not specified for SAE J404 4120.
Can GB/T 3077 20CrMnMo be substituted with SAE J404 4120?
GB/T 3077 20CrMnMo and SAE J404 4120 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.