JIS G4105 SCM420 vs BS 970 (Part 1) 708H20

Strong Match — 86.1% match based on chemical composition and mechanical property overlap.

JIS G4105 SCM420 (JIS G4105:1979) and BS 970 (Part 1) 708H20 (BS 970 (Part 1):1983) are both steel grades. Both fall under the Alloy Steel category. JIS G4105 SCM420 is typically used for case hardened gears, cams, pins, shafts, while BS 970 (Part 1) 708H20 is commonly used for case hardening steel supplied to specified hardenability limits (end quench test, table 10).. JIS G4105 SCM420 is defined under Japanese Industrial Standards (JIS), originating from Japan, while BS 970 (Part 1) 708H20 is defined under British Standards (BS), originating from United Kingdom.

As per chemical composition, JIS G4105 SCM420 vs BS 970 (Part 1) 708H20 is a 86.1% match. Mechanical property data is not available for both grades, so this factor could not be scored. Combined, this makes them a strong match overall at 86.1%.

Frequently Compared With JIS G4105 SCM420:
NF A35-565 100C6 UNI 11234 100Cr6 GB/T 3077 12Cr2Ni4A GOST 4543 12HN3A IS 1570 (Part 4) 103Cr6 IS 1570 (Part 4) 105Cr5 IS 4367 10Cr9Mo10 IS 4367 07Cr4Mo6 IS 1570 (Part 7) 10Cr36Mo10H IS 1570 (Part 4) 103Cr4 IS 1570 (Part 4) 10Cr20Mo6 IS 1570 (Part 4) 07Cr4Mo6
Match Breakdown
CHEMISTRY MATCH
86.1%
MECHANICAL MATCH
No shared data
OVERALL
86.1%
Specifications
Property JIS G4105 SCM420 BS 970 (Part 1) 708H20
Standard JIS G4105:1979 BS 970 (Part 1):1983
Category Alloy Steel Alloy Steel
C (%) 0.18–0.23 0.17-0.23
Si (%) 0.15–0.35 Not specified
Mn (%) 0.60–0.90 0.60-0.90
Cr (%) 0.90–1.20 0.85-1.15
Mo (%) 0.15–0.30 0.15-0.25
P (%) Not specified <=0.035
S (%) Not specified <=0.040
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property JIS G4105 SCM420 BS 970 (Part 1) 708H20
Tensile Strength ≥830 MPa Not specified
Case Hardness HRC 58–62 Not specified
Core Hardness HB 235–293 Not specified
Typical Applications
JIS G4105 SCM420
Case hardened gears, cams, pins, shafts
BS 970 (Part 1) 708H20
Case hardening steel supplied to specified hardenability limits (end quench test, Table 10).
Key Differences
Can JIS G4105 SCM420 Be Substituted With BS 970 (Part 1) 708H20?
JIS G4105 SCM420 and BS 970 (Part 1) 708H20 overlap closely enough on chemistry and mechanical properties that BS 970 (Part 1) 708H20 is often considered as a substitute for JIS G4105 SCM420 in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.
Forms & Sizes Available on M-EX
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)
BS 970 (Part 1) 708H20
No active listings currently.
On M-EX Right Now
JIS G4105 SCM420
3 active listings and RFQs →
BS 970 (Part 1) 708H20
0 active listings and RFQs →
Frequently Asked Questions
What is the difference between JIS G4105 SCM420 and BS 970 (Part 1) 708H20?
JIS G4105 SCM420 specifies Si which is not specified for BS 970 (Part 1) 708H20. BS 970 (Part 1) 708H20 specifies P, S which are not specified for JIS G4105 SCM420.
Can JIS G4105 SCM420 be substituted with BS 970 (Part 1) 708H20?
JIS G4105 SCM420 and BS 970 (Part 1) 708H20 overlap closely enough on chemistry and mechanical properties that BS 970 (Part 1) 708H20 is often considered as a substitute for JIS G4105 SCM420 in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.