Post Stock Login Register

SAE J404 4340 vs JIS G4103 SNCM439

Strong Match — 85.7% match based on chemical composition and mechanical property overlap.

SAE J404 4340 (SAE J404:2009) and JIS G4103 SNCM439 (JIS G4103:1979) 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 JIS G4103 SNCM439 is commonly used for crankshafts, gears, heavy duty shafts, aircraft components. SAE J404 4340 is defined under SAE International, originating from United States, while JIS G4103 SNCM439 is defined under Japanese Industrial Standards (JIS), originating from Japan.

As per chemical composition, SAE J404 4340 vs JIS G4103 SNCM439 is a 85.7% 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 85.7%.

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
85.7%
MECHANICAL MATCH
No shared data
OVERALL
85.7%
Specifications
Property SAE J404 4340 JIS G4103 SNCM439
Standard SAE J404:2009 JIS G4103:1979
Category Alloy Steel Alloy Steel
C (%) 0.38-0.43 0.36–0.43
Cr (%) 0.70-0.90 0.60–1.00
Mn (%) 0.60-0.80 0.60–0.90
Mo (%) 0.20-0.30 0.15–0.30
Ni (%) 1.65-2.00 1.60–2.00
P (%) <=0.030 Not specified
S (%) <=0.040 Not specified
Si (%) 0.15-0.35 0.15–0.35
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 JIS G4103 SNCM439
Tensile Strength Not specified ≥980 MPa
Yield Strength Not specified ≥835 MPa
Elongation Not specified ≥12%
Hardness Not specified 293–352 HB
Typical Applications
SAE J404 4340
Aircraft parts, heavy duty gears, crankshafts
JIS G4103 SNCM439
Crankshafts, gears, heavy duty shafts, aircraft components
Key Differences
Can SAE J404 4340 Be Substituted With JIS G4103 SNCM439?
SAE J404 4340 and JIS G4103 SNCM439 overlap closely enough on chemistry and mechanical properties that JIS G4103 SNCM439 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)
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)
On M-EX Right Now
SAE J404 4340
32 active listings and RFQs →
JIS G4103 SNCM439
3 active listings and RFQs →
Frequently Asked Questions
What is the difference between SAE J404 4340 and JIS G4103 SNCM439?
SAE J404 4340 specifies P, S which are not specified for JIS G4103 SNCM439.
Can SAE J404 4340 be substituted with JIS G4103 SNCM439?
SAE J404 4340 and JIS G4103 SNCM439 overlap closely enough on chemistry and mechanical properties that JIS G4103 SNCM439 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.