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SAE J404 4120 vs JIS G4105 SCM420

Close Alternative — 77.9% match based on chemical composition and mechanical property overlap.

SAE J404 4120 (SAE J404:2000) and JIS G4105 SCM420 (JIS G4105:1979) are both steel grades. Both fall under the Alloy Steel category. SAE J404 4120 is typically used for chemistry-only alloy steel grade; see the composition notes for product scope, while JIS G4105 SCM420 is commonly used for case hardened gears, cams, pins, shafts. SAE J404 4120 is defined under SAE International, originating from United States, while JIS G4105 SCM420 is defined under Japanese Industrial Standards (JIS), originating from Japan.

As per chemical composition, SAE J404 4120 vs JIS G4105 SCM420 is a 77.9% 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 77.9%.

Frequently Compared With SAE J404 4120:
IS 1570 (Part 4) 105Cr5 UNI 11234 100Cr6 IS 1570 (Part 4) 103Cr4 IS 1570 (Part 4) 10Cr20Mo6 IS 4367 10Cr9Mo10 IS 1570 (Part 7) 12Cr2Mo5V2H NF A35-565 100C6 IS 1570 (Part 4) 103Cr6 IS 1570 (Part 4) 07Cr4Mo6 IS 1570 (Part 7) 10Mo6H IS 11169 (Part 1) 10Ni5Cr4 IS 4367 07Cr4Mo6
Match Breakdown
CHEMISTRY MATCH
77.9%
MECHANICAL MATCH
No shared data
OVERALL
77.9%
Specifications
Property SAE J404 4120 JIS G4105 SCM420
Standard SAE J404:2000 JIS G4105:1979
Category Alloy Steel Alloy Steel
C (%) 0.18-0.23 0.18–0.23
Cr (%) 0.40-0.60 0.90–1.20
Mn (%) 0.90-1.20 0.60–0.90
Mo (%) 0.13-0.20 0.15–0.30
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 4120 JIS G4105 SCM420
Tensile Strength Not specified ≥830 MPa
Case Hardness HRC Not specified 58–62
Core Hardness HB Not specified 235–293
Typical Applications
SAE J404 4120
Chemistry-only alloy steel grade; see the composition notes for product scope
JIS G4105 SCM420
Case hardened gears, cams, pins, shafts
Key Differences
Can SAE J404 4120 Be Substituted With JIS G4105 SCM420?
SAE J404 4120 and JIS G4105 SCM420 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.
Forms & Sizes Available on M-EX
SAE J404 4120
No active listings currently.
JIS G4105 SCM420
Round Bar → (3 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 4800–6400 mm (188.98–251.97 in)
On M-EX Right Now
SAE J404 4120
0 active listings and RFQs →
JIS G4105 SCM420
3 active listings and RFQs →
Frequently Asked Questions
What is the difference between SAE J404 4120 and JIS G4105 SCM420?
SAE J404 4120 specifies P, S which are not specified for JIS G4105 SCM420.
Can SAE J404 4120 be substituted with JIS G4105 SCM420?
SAE J404 4120 and JIS G4105 SCM420 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.