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SAE J404 4340 vs GB/T 3077 12Cr2Ni4A

Minimal Match — 35% match based on chemical composition and mechanical property overlap.

SAE J404 4340 (SAE J404:2009) and GB/T 3077 12Cr2Ni4A (GB/T 3077-2015) are both steel grades. Both fall under the Alloy Steel category. SAE J404 4340 is typically used for aircraft parts, heavy duty gears, crankshafts, while GB/T 3077 12Cr2Ni4A is commonly used for used for gears, shafts, pinions, aircraft parts, heavy-duty bearings, and transmission components.. SAE J404 4340 is defined under SAE International, originating from United States, while GB/T 3077 12Cr2Ni4A is defined under Guobiao Standards (GB/T), originating from China.

As per chemical composition, SAE J404 4340 vs GB/T 3077 12Cr2Ni4A is a 57.4% match. Mechanical property data is not available for both grades, so this factor could not be scored. Combined, this makes them a minimal match overall at 35%.

Frequently Compared With SAE J404 4340:
NF A35-565 100C6 GOST 4543 12HN3A UNI 11234 100Cr6 IS 1570 (Part 4) 07Cr4Mo6 IS 1570 (Part 7) 10Cr36Mo10H IS 4367 07Cr4Mo6 IS 1570 (Part 4) 103Cr6 IS 1570 (Part 4) 10Cr20Mo6 IS 1570 (Part 4) 103Cr4 IS 1570 (Part 4) 105Cr5 IS 4367 10Cr9Mo10 EN 10028-2 10CrMo9-10
Match Breakdown
CHEMISTRY MATCH
57.4%
MECHANICAL MATCH
No shared data
OVERALL
35%
Specifications
Property SAE J404 4340 GB/T 3077 12Cr2Ni4A
Standard SAE J404:2009 GB/T 3077-2015
Category Alloy Steel Alloy Steel
C (%) 0.38-0.43 0.10-0.15
Cr (%) 0.70-0.90 1.25-1.65
Mn (%) 0.60-0.80 0.30-0.60
Mo (%) 0.20-0.30 Not specified
Ni (%) 1.65-2.00 3.25-3.75
P (%) <=0.030 0.025 max
S (%) <=0.040 0.025 max
Si (%) 0.15-0.35 0.17-0.37
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property SAE J404 4340 GB/T 3077 12Cr2Ni4A
Tensile Strength Not specified 980-1180 MPa
Yield Strength Not specified 785-980 MPa
Elongation Not specified 10-14%
Hardness Not specified 58-62 HRC (case)
Typical Applications
SAE J404 4340
Aircraft parts, heavy duty gears, crankshafts
GB/T 3077 12Cr2Ni4A
Used for gears, shafts, pinions, aircraft parts, heavy-duty bearings, and transmission components.
Key Differences
Can SAE J404 4340 Be Substituted With GB/T 3077 12Cr2Ni4A?
SAE J404 4340 and GB/T 3077 12Cr2Ni4A 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
SAE J404 4340
Round Bar → (25 listings)
Diameter: 50–100 mm (1.97–3.94 in)
Length: 3800–7000 mm (149.61–275.59 in)
Forging → (4 listings)
Diameter: 150–200 mm (5.91–7.87 in)
Length: 500–1500 mm (19.69–59.06 in)
Flat Bar → (3 listings)
Thickness: 30–30 mm (1.18–1.18 in)
Width: 120–120 mm (4.72–4.72 in)
Length: 2500–3000 mm (98.43–118.11 in)
GB/T 3077 12Cr2Ni4A
Round Bar → (2 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 5000–6600 mm (196.85–259.84 in)
On M-EX Right Now
SAE J404 4340
32 active listings and RFQs →
GB/T 3077 12Cr2Ni4A
2 active listings and RFQs →
Frequently Asked Questions
What is the difference between SAE J404 4340 and GB/T 3077 12Cr2Ni4A?
SAE J404 4340 specifies Mo which is not specified for GB/T 3077 12Cr2Ni4A.
Can SAE J404 4340 be substituted with GB/T 3077 12Cr2Ni4A?
SAE J404 4340 and GB/T 3077 12Cr2Ni4A 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.