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ASTM A681 P21 vs GB/T 699 20

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

ASTM A681 P21 (ASTM A681:2008) and GB/T 699 20 (GB/T 699:2015) are both steel grades. ASTM A681 P21 is classified under Tool & Die Steels, while GB/T 699 20 is classified under Carbon Steel — a different category, which is worth noting alongside the chemistry match below. ASTM A681 P21 is typically used for tools, dies and fixtures (clause 1.2), while GB/T 699 20 is commonly used for used for shafts, pins, carburized parts, welded structures, bolts, and machine brackets.. ASTM A681 P21 is defined under ASTM International, originating from United States, while GB/T 699 20 is defined under Guobiao Standards (GB/T), originating from China.

As per chemical composition, ASTM A681 P21 vs GB/T 699 20 is a 65.2% 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 ASTM A681 P21:
GB/T 1299 4Cr5MoSiV DIN EN ISO 4957 1.2379 IS 1570 (Part 6) 103T3 GOST 5950 4H5MFS1 EN ISO 4957 1.2316 DIN EN ISO 4957 1.2344 EN ISO 683-17 100Cr6 IS 1570 (Part 6) 118T3 IS 1570 (Part 6) 133T3 GOST 5950 3H2W8F GB/T 1299 4Cr5MoSiV1 GOST 5950 4H5MFS
Match Breakdown
CHEMISTRY MATCH
65.2%
MECHANICAL MATCH
No shared data
OVERALL
65%
Specifications
Property ASTM A681 P21 GB/T 699 20
Standard ASTM A681:2008 GB/T 699:2015
Category Tool & Die Steels Carbon Steel
C (%) 0.18-0.22 0.17-0.23
Mn (%) 0.20-0.40 0.35-0.65
P (%) <=0.030 <=0.035
S (%) <=0.030 <=0.035
Si (%) 0.20-0.40 0.17-0.37
Cr (%) 0.20-0.30 <=0.25
V (%) 0.15-0.25 Not specified
Ni (%) 3.90-4.25 <=0.30
Al (%) 1.05-1.25 Not specified
Cu (%) Not specified <=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 ASTM A681 P21 GB/T 699 20
Tensile Strength Not specified >=410 MPa
Yield Strength Not specified >=245 MPa
Elongation Not specified >=25%
Hardness Not specified <=156 HB (as delivered, not heat treated)
Condition Not specified Normalized 25 mm sample blank, bars up to 80 mm; hardness for delivery state
Typical Applications
ASTM A681 P21
Tools, dies and fixtures (clause 1.2)
GB/T 699 20
Used for shafts, pins, carburized parts, welded structures, bolts, and machine brackets.
Key Differences
Can ASTM A681 P21 Be Substituted With GB/T 699 20?
ASTM A681 P21 and GB/T 699 20 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
ASTM A681 P21
No active listings currently.
GB/T 699 20
Round Bar → (2 listings)
Diameter: 40–40 mm (1.57–1.57 in)
Length: 6200–6700 mm (244.09–263.78 in)
On M-EX Right Now
ASTM A681 P21
0 active listings and RFQs →
GB/T 699 20
2 active listings and RFQs →
Frequently Asked Questions
What is the difference between ASTM A681 P21 and GB/T 699 20?
Different category: ASTM A681 P21 is Tool & Die Steels, GB/T 699 20 is Carbon Steel. ASTM A681 P21 specifies V, Al which are not specified for GB/T 699 20. GB/T 699 20 specifies Cu which is not specified for ASTM A681 P21.
Can ASTM A681 P21 be substituted with GB/T 699 20?
ASTM A681 P21 and GB/T 699 20 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.