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JIS G4103 SNCM420 vs BS 970 (Part 3) 805M20

Close Alternative — 76.3% match based on chemical composition and mechanical property overlap.

JIS G4103 SNCM420 (JIS G4103:1979) and BS 970 (Part 3) 805M20 (BS 970 (Part 3):1991) are both steel grades. Both fall under the Alloy Steel category. JIS G4103 SNCM420 is typically used for used in automotive gears, transmission parts, shafts, pinions, camshafts, and industrial equipment., while BS 970 (Part 3) 805M20 is commonly used for bright cold finished bars (cold drawn, turned or precision ground) for general engineering purposes, in straight lengths; alloy case hardening steel (table 15). JIS G4103 SNCM420 is defined under Japanese Industrial Standards (JIS), originating from Japan, while BS 970 (Part 3) 805M20 is defined under British Standards (BS), originating from United Kingdom.

As per chemical composition, JIS G4103 SNCM420 vs BS 970 (Part 3) 805M20 is a 76.3% 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 76.3%.

Frequently Compared With JIS G4103 SNCM420:
UNI 11234 100Cr6 GOST 4543 12HN3A NF A35-565 100C6 GB/T 3077 12Cr2Ni4A IS 1570 (Part 4) 07Cr4Mo6 IS 1570 (Part 4) 103Cr6 IS 4367 07Cr4Mo6 IS 1570 (Part 4) 10Cr20Mo6 IS 4367 10Cr9Mo10 IS 1570 (Part 4) 103Cr4 IS 1570 (Part 4) 105Cr5 IS 1570 (Part 7) 10Cr36Mo10H
Match Breakdown
CHEMISTRY MATCH
76.3%
MECHANICAL MATCH
No shared data
OVERALL
76.3%
Specifications
Property JIS G4103 SNCM420 BS 970 (Part 3) 805M20
Standard JIS G4103:1979 BS 970 (Part 3):1991
Category Alloy Steel Alloy Steel
C (%) 0.17-0.23 0.17-0.23
Si (%) 0.15-0.35 0.10-0.40
Mn (%) 0.40-0.70 0.60-0.95
P (%) 0.030 max <=0.04
S (%) 0.030 max <=0.05
Ni (%) 1.50-2.00 0.35-0.75
Cr (%) 0.40-0.80 0.35-0.65
Mo (%) 0.15-0.30 0.15-0.25
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property JIS G4103 SNCM420 BS 970 (Part 3) 805M20
Tensile Strength 780-930 MPa Not specified
Yield Strength 590 MPa min Not specified
Elongation 14% min Not specified
Hardness 217-269 HB Not specified
Typical Applications
JIS G4103 SNCM420
Used in automotive gears, transmission parts, shafts, pinions, camshafts, and industrial equipment.
BS 970 (Part 3) 805M20
Bright cold finished bars (cold drawn, turned or precision ground) for general engineering purposes, in straight lengths; alloy case hardening steel (Table 15)
Can JIS G4103 SNCM420 Be Substituted With BS 970 (Part 3) 805M20?
JIS G4103 SNCM420 and BS 970 (Part 3) 805M20 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
JIS G4103 SNCM420
Round Bar → (2 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 5900–6000 mm (232.28–236.22 in)
BS 970 (Part 3) 805M20
No active listings currently.
On M-EX Right Now
JIS G4103 SNCM420
2 active listings and RFQs →
BS 970 (Part 3) 805M20
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Frequently Asked Questions
What is the difference between JIS G4103 SNCM420 and BS 970 (Part 3) 805M20?
Both grades share a similar composition profile; see the specification table above for the exact chemistry and mechanical property values.
Can JIS G4103 SNCM420 be substituted with BS 970 (Part 3) 805M20?
JIS G4103 SNCM420 and BS 970 (Part 3) 805M20 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.