Close Alternative — 83.4% match
based on chemical composition and mechanical property overlap.
SAE J404 E4340 (SAE J404:2000) and JIS G4103 SNCM240 (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 SNCM240 is commonly used for used in gears, shafts, axles, crankshafts, bolts, and machine tool components..
SAE J404 E4340 is defined under SAE International, originating from United States, while JIS G4103 SNCM240 is defined under Japanese Industrial Standards (JIS), originating from Japan.
As per chemical composition, SAE J404 E4340 vs JIS G4103 SNCM240 is a 83.4% 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 83.4%.
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 SNCM240
Tensile Strength
Not specified
850-1000 MPa
Yield Strength
Not specified
685 MPa min
Elongation
Not specified
13% min
Hardness
Not specified
240-300 HB
Typical Applications
SAE J404 E4340
Chemistry-only alloy steel grade; see the composition notes for product scope
JIS G4103 SNCM240
Used in gears, shafts, axles, crankshafts, bolts, and machine tool components.
Can SAE J404 E4340 Be Substituted With JIS G4103 SNCM240?
SAE J404 E4340 and JIS G4103 SNCM240 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 SNCM240?
Both grades share a similar composition profile; see the specification table above for the exact chemistry and mechanical property values.
Can SAE J404 E4340 be substituted with JIS G4103 SNCM240?
SAE J404 E4340 and JIS G4103 SNCM240 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.