Close Alternative — 84.6% match
based on chemical composition and mechanical property overlap.
SAE J404 E4340 (SAE J404:2000) and JIS G4103 SNCM439 (JIS G4103:1979) are both steel grades.
Both fall under the Alloy Steel category.
SAE J404 E4340 is typically used for chemistry-only alloy steel grade; see the composition notes for product scope, while JIS G4103 SNCM439 is commonly used for crankshafts, gears, heavy duty shafts, aircraft components.
SAE J404 E4340 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 E4340 vs JIS G4103 SNCM439 is a 84.6% 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 84.6%.
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 E4340
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 E4340
Chemistry-only alloy steel grade; see the composition notes for product scope
JIS G4103 SNCM439
Crankshafts, gears, heavy duty shafts, aircraft components
Key Differences
SAE J404 E4340 specifies P, S which are not specified for JIS G4103 SNCM439.
Can SAE J404 E4340 Be Substituted With JIS G4103 SNCM439?
SAE J404 E4340 and JIS G4103 SNCM439 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.
What is the difference between SAE J404 E4340 and JIS G4103 SNCM439?
SAE J404 E4340 specifies P, S which are not specified for JIS G4103 SNCM439.
Can SAE J404 E4340 be substituted with JIS G4103 SNCM439?
SAE J404 E4340 and JIS G4103 SNCM439 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.