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GB/T 3077 42CrMo vs BS 970 (Part 3) 708M40

Strong Match — 87.2% match based on chemical composition and mechanical property overlap.

GB/T 3077 42CrMo (GB/T 3077:2015) and BS 970 (Part 3) 708M40 (BS 970 (Part 3):1991) are both steel grades. Both fall under the Alloy Steel category. GB/T 3077 42CrMo is typically used for gears, heavy shafts, axles, bolts, pressure vessels, forgings, while BS 970 (Part 3) 708M40 is commonly used for bright cold finished bars (cold drawn, turned or precision ground) for general engineering purposes, in straight lengths; alloy direct hardening steel (table 16). GB/T 3077 42CrMo is defined under Guobiao Standards (GB/T), originating from China, while BS 970 (Part 3) 708M40 is defined under British Standards (BS), originating from United Kingdom.

As per chemical composition, GB/T 3077 42CrMo vs BS 970 (Part 3) 708M40 is a 87.2% 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 87.2%.

Frequently Compared With GB/T 3077 42CrMo:
NF A35-565 100C6 GOST 4543 12HN3A UNI 11234 100Cr6 GB/T 3077 12Cr2Ni4A IS 1570 (Part 4) 103Cr6 IS 1570 (Part 4) 103Cr4 IS 4367 07Cr4Mo6 IS 1570 (Part 4) 07Cr4Mo6 IS 4367 10Cr9Mo10 IS 1570 (Part 7) 10Cr36Mo10H IS 1570 (Part 4) 105Cr5 IS 1570 (Part 4) 10Cr20Mo6
Match Breakdown
CHEMISTRY MATCH
87.2%
MECHANICAL MATCH
No shared data
OVERALL
87.2%
Specifications
Property GB/T 3077 42CrMo BS 970 (Part 3) 708M40
Standard GB/T 3077:2015 BS 970 (Part 3):1991
Category Alloy Steel Alloy Steel
C (%) 0.38-0.45 0.36-0.44
Si (%) 0.17-0.37 0.10-0.40
Mn (%) 0.50-0.80 0.70-1.00
Cr (%) 0.90-1.20 0.90-1.20
Mo (%) 0.15-0.25 0.15-0.25
P (%) <=0.030 <=0.035
S (%) <=0.030 <=0.040
Cu (%) <=0.30 Not specified
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property GB/T 3077 42CrMo BS 970 (Part 3) 708M40
Tensile Strength >=1080 MPa Not specified
Yield Strength >=930 MPa Not specified
Elongation >=12% Not specified
Hardness <=229 HB Not specified
Condition Quenched and tempered, test sample 25 mm; hardness is for bars delivered annealed or high temperature tempered Not specified
Typical Applications
GB/T 3077 42CrMo
gears, heavy shafts, axles, bolts, pressure vessels, forgings
BS 970 (Part 3) 708M40
Bright cold finished bars (cold drawn, turned or precision ground) for general engineering purposes, in straight lengths; alloy direct hardening steel (Table 16)
Key Differences
Can GB/T 3077 42CrMo Be Substituted With BS 970 (Part 3) 708M40?
GB/T 3077 42CrMo and BS 970 (Part 3) 708M40 overlap closely enough on chemistry and mechanical properties that BS 970 (Part 3) 708M40 is often considered as a substitute for GB/T 3077 42CrMo 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
GB/T 3077 42CrMo
Round Bar → (2 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 4900–7000 mm (192.91–275.59 in)
BS 970 (Part 3) 708M40
No active listings currently.
On M-EX Right Now
GB/T 3077 42CrMo
2 active listings and RFQs →
BS 970 (Part 3) 708M40
0 active listings and RFQs →
Frequently Asked Questions
What is the difference between GB/T 3077 42CrMo and BS 970 (Part 3) 708M40?
GB/T 3077 42CrMo specifies Cu which is not specified for BS 970 (Part 3) 708M40.
Can GB/T 3077 42CrMo be substituted with BS 970 (Part 3) 708M40?
GB/T 3077 42CrMo and BS 970 (Part 3) 708M40 overlap closely enough on chemistry and mechanical properties that BS 970 (Part 3) 708M40 is often considered as a substitute for GB/T 3077 42CrMo in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.