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SAE J404 4340 vs GB/T 3077 40CrNi2Mo

Strong Match — 95.9% match based on chemical composition and mechanical property overlap.

SAE J404 4340 (SAE J404:2009) and GB/T 3077 40CrNi2Mo (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 40CrNi2Mo is commonly used for hot-rolled or forged structural alloy steel bars. SAE J404 4340 is defined under SAE International, originating from United States, while GB/T 3077 40CrNi2Mo is defined under Guobiao Standards (GB/T), originating from China.

As per chemical composition, SAE J404 4340 vs GB/T 3077 40CrNi2Mo is a 95.9% match. Mechanical property data is not available for both grades, so this factor could not be scored. Combined, this makes them a strong match overall at 95.9%.

Frequently Compared With SAE J404 4340:
GB/T 3077 12Cr2Ni4A 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
Match Breakdown
CHEMISTRY MATCH
95.9%
MECHANICAL MATCH
No shared data
OVERALL
95.9%
Specifications
Property SAE J404 4340 GB/T 3077 40CrNi2Mo
Standard SAE J404:2009 GB/T 3077:2015
Category Alloy Steel Alloy Steel
C (%) 0.38-0.43 0.38-0.43
Cr (%) 0.70-0.90 0.70-0.90
Mn (%) 0.60-0.80 0.60-0.80
Mo (%) 0.20-0.30 0.20-0.30
Ni (%) 1.65-2.00 1.65-2.00
P (%) <=0.030 <=0.030
S (%) <=0.040 <=0.030
Si (%) 0.15-0.35 0.17-0.37
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 SAE J404 4340 GB/T 3077 40CrNi2Mo
Tensile Strength Not specified >=1050 MPa
Yield Strength Not specified >=980 MPa
Elongation Not specified >=12%
Hardness Not specified <=269 HB
Condition Not specified Quenched and tempered, test sample 25 mm; hardness is for bars delivered annealed or high temperature tempered
Typical Applications
SAE J404 4340
Aircraft parts, heavy duty gears, crankshafts
GB/T 3077 40CrNi2Mo
Hot-rolled or forged structural alloy steel bars
Key Differences
Can SAE J404 4340 Be Substituted With GB/T 3077 40CrNi2Mo?
SAE J404 4340 and GB/T 3077 40CrNi2Mo overlap closely enough on chemistry and mechanical properties that GB/T 3077 40CrNi2Mo is often considered as a substitute for SAE J404 4340 in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.
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 40CrNi2Mo
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On M-EX Right Now
SAE J404 4340
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GB/T 3077 40CrNi2Mo
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Frequently Asked Questions
What is the difference between SAE J404 4340 and GB/T 3077 40CrNi2Mo?
GB/T 3077 40CrNi2Mo specifies Cu which is not specified for SAE J404 4340.
Can SAE J404 4340 be substituted with GB/T 3077 40CrNi2Mo?
SAE J404 4340 and GB/T 3077 40CrNi2Mo overlap closely enough on chemistry and mechanical properties that GB/T 3077 40CrNi2Mo is often considered as a substitute for SAE J404 4340 in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.