Close Alternative — 79.6% match
based on chemical composition and mechanical property overlap.
BS 970 (Part 1) 708M20 (BS 970 (Part 1):1991) and SAE J404 4135 (SAE J404:2009) are both steel grades.
Both fall under the Alloy Steel category.
BS 970 (Part 1) 708M20 is typically used for case hardening steel (section four), while SAE J404 4135 is commonly used for gears, shafts, pressure vessels, high tensile bolts.
BS 970 (Part 1) 708M20 is defined under British Standards (BS), originating from United Kingdom, while SAE J404 4135 is defined under SAE International, originating from United States.
As per chemical composition, BS 970 (Part 1) 708M20 vs SAE J404 4135 is a 79.6% 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 79.6%.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property
BS 970 (Part 1) 708M20
SAE J404 4135
Condition
Case hardened, 19 mm test bar
Not specified
Tensile Strength
930 MPa min
Not specified
Elongation
10 % min
Not specified
Typical Applications
BS 970 (Part 1) 708M20
Case hardening steel (section four)
SAE J404 4135
Gears, shafts, pressure vessels, high tensile bolts
Key Differences
SAE J404 4135 specifies P, S, Si which are not specified for BS 970 (Part 1) 708M20.
Can BS 970 (Part 1) 708M20 Be Substituted With SAE J404 4135?
BS 970 (Part 1) 708M20 and SAE J404 4135 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 BS 970 (Part 1) 708M20 and SAE J404 4135?
SAE J404 4135 specifies P, S, Si which are not specified for BS 970 (Part 1) 708M20.
Can BS 970 (Part 1) 708M20 be substituted with SAE J404 4135?
BS 970 (Part 1) 708M20 and SAE J404 4135 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.