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GB/T 699 40 vs BS 970 (Part 3) 635M15

Related Material — 65% match based on chemical composition and mechanical property overlap.

GB/T 699 40 (GB/T 699:2015) and BS 970 (Part 3) 635M15 (BS 970 (Part 3):1991) are both steel grades. GB/T 699 40 is classified under Carbon Steel, while BS 970 (Part 3) 635M15 is classified under Alloy Steel — a different category, which is worth noting alongside the chemistry match below. GB/T 699 40 is typically used for used for gears, shafts, axles, crankshafts, couplings, and machine spindles., while BS 970 (Part 3) 635M15 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). GB/T 699 40 is defined under Guobiao Standards (GB/T), originating from China, while BS 970 (Part 3) 635M15 is defined under British Standards (BS), originating from United Kingdom.

As per chemical composition, GB/T 699 40 vs BS 970 (Part 3) 635M15 is a 66% match. Mechanical property data is not available for both grades, so this factor could not be scored. Combined, this makes them a related material overall at 65%.

Frequently Compared With GB/T 699 40:
BS 970 (Part 1) 040A10 BS 970 (Part 3) 070M55 BS 970 (Part 1) 040A04 BS 970 (Part 1) 045A10 BS 970 (Part 3) 045A10 BS 970 (Part 1) 060A40 BS 970 (Part 1) 040A12 BS 970 (Part 3) 045M10 BS 970 (Part 1) 055M15 BS 970 (Part 1) 045A10 BS 970 (Part 1) 045M10 BS 970 (Part 1) 045M10
Match Breakdown
CHEMISTRY MATCH
66%
MECHANICAL MATCH
No shared data
OVERALL
65%
Specifications
Property GB/T 699 40 BS 970 (Part 3) 635M15
Standard GB/T 699:2015 BS 970 (Part 3):1991
Category Carbon Steel Alloy Steel
C (%) 0.37-0.44 0.12-0.18
Si (%) 0.17-0.37 0.10-0.40
Mn (%) 0.50-0.80 0.60-0.90
P (%) <=0.035 <=0.04
S (%) <=0.035 <=0.05
Cr (%) <=0.25 0.4-0.80
Ni (%) <=0.30 0.70-1.10
Cu (%) <=0.25 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 699 40 BS 970 (Part 3) 635M15
Tensile Strength >=570 MPa Not specified
Yield Strength >=335 MPa Not specified
Elongation >=19% Not specified
Hardness <=217 HB (as delivered, not heat treated) Not specified
Condition Normalized 25 mm sample blank, bars up to 80 mm; hardness for delivery state Not specified
Typical Applications
GB/T 699 40
Used for gears, shafts, axles, crankshafts, couplings, and machine spindles.
BS 970 (Part 3) 635M15
Bright cold finished bars (cold drawn, turned or precision ground) for general engineering purposes, in straight lengths; alloy case hardening steel (Table 15)
Key Differences
Can GB/T 699 40 Be Substituted With BS 970 (Part 3) 635M15?
GB/T 699 40 and BS 970 (Part 3) 635M15 share some compositional similarity but differ enough that substitution should not be assumed. Review the differences above carefully, and consult the applicable standard or a metallurgist before using one in place of the other.
Forms & Sizes Available on M-EX
GB/T 699 40
Round Bar → (2 listings)
Diameter: 40–40 mm (1.57–1.57 in)
Length: 5000–7000 mm (196.85–275.59 in)
BS 970 (Part 3) 635M15
No active listings currently.
On M-EX Right Now
GB/T 699 40
2 active listings and RFQs →
BS 970 (Part 3) 635M15
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Frequently Asked Questions
What is the difference between GB/T 699 40 and BS 970 (Part 3) 635M15?
Different category: GB/T 699 40 is Carbon Steel, BS 970 (Part 3) 635M15 is Alloy Steel. GB/T 699 40 specifies Cu which is not specified for BS 970 (Part 3) 635M15.
Can GB/T 699 40 be substituted with BS 970 (Part 3) 635M15?
GB/T 699 40 and BS 970 (Part 3) 635M15 share some compositional similarity but differ enough that substitution should not be assumed. Review the differences above carefully, and consult the applicable standard or a metallurgist before using one in place of the other.