Close Alternative — 78.9% match
based on chemical composition and mechanical property overlap.
SAE J404 4120 (SAE J404:2009) and EN 10084 20MoCr4 (EN 10084:2008) are both steel grades.
Both fall under the Alloy Steel category.
SAE J404 4120 is typically used for used for gears, crankshafts, studs, pins, machinery parts, and transmission components., while EN 10084 20MoCr4 is commonly used for case hardened machine parts: carburized or carbonitrided, then hardened (clause 3.1).
SAE J404 4120 is defined under SAE International, originating from United States, while EN 10084 20MoCr4 is defined under European Standard (EN), originating from Europe.
As per chemical composition, SAE J404 4120 vs EN 10084 20MoCr4 is a 78.9% 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 78.9%.
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 4120
EN 10084 20MoCr4
Condition
Not specified
Soft annealed
Hardenability
Not specified
+H band at 1.5 mm from the quenched end: 41 to 49 HRC
Hardness
Not specified
Soft annealed: 207 HB max
Typical Applications
SAE J404 4120
Used for gears, crankshafts, studs, pins, machinery parts, and transmission components.
EN 10084 20MoCr4
Case hardened machine parts: carburized or carbonitrided, then hardened (clause 3.1)
Can SAE J404 4120 Be Substituted With EN 10084 20MoCr4?
SAE J404 4120 and EN 10084 20MoCr4 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 4120 and EN 10084 20MoCr4?
Both grades share a similar composition profile; see the specification table above for the exact chemistry and mechanical property values.
Can SAE J404 4120 be substituted with EN 10084 20MoCr4?
SAE J404 4120 and EN 10084 20MoCr4 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.