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AISI D2 KNL vs BS 970 (Part 1) 709M40

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

AISI D2 KNL (ASTM A681) and BS 970 (Part 1) 709M40 (BS 970 (Part 1):1991) are both steel grades. AISI D2 KNL is classified under Tool & Die Steels, while BS 970 (Part 1) 709M40 is classified under Alloy Steel — a different category, which is worth noting alongside the chemistry match below. AISI D2 KNL is typically used for blanking dies, forming dies, thread rolling dies, punches, shear blades, gauges, broaches, drawing dies, while BS 970 (Part 1) 709M40 is commonly used for used for aircraft parts, heavy-duty gears, transmission shafts, connecting rods, crankshafts, and engineering fasteners.. AISI D2 KNL is defined under AISI, originating from United States, while BS 970 (Part 1) 709M40 is defined under British Standards (BS), originating from United Kingdom.

As per chemical composition, AISI D2 KNL vs BS 970 (Part 1) 709M40 is a 70.3% 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 AISI D2 KNL:
DIN EN ISO 4957 1.2379 EN ISO 683-17 100Cr6 GB/T 1299 3Cr2W8V DIN EN ISO 4957 1.2344 EN ISO 4957 1.2316 GB/T 1299 4Cr5MoSiV GB/T 1299 4Cr5MoSiV1 GOST 5950 4H5MFS GOST 5950 3H2W8F GOST 5950 4H5MFS1 AISI 52100 IS 1570 (Part 6) 103T3
Match Breakdown
CHEMISTRY MATCH
70.3%
MECHANICAL MATCH
No shared data
OVERALL
65%
Specifications
Property AISI D2 KNL BS 970 (Part 1) 709M40
Standard ASTM A681 BS 970 (Part 1):1991
Category Tool & Die Steels Alloy Steel
C (%) 1.40–1.60 0.36-0.44
Mn (%) ≤0.60 0.70-1.00
Si (%) ≤0.40 Not specified
Cr (%) 11.00–13.00 0.90-1.20
Mo (%) 0.70–1.20 0.25-0.35
V (%) ≤1.00 Not specified
S (%) ≤0.030 Not specified
P (%) ≤0.030 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 AISI D2 KNL BS 970 (Part 1) 709M40
Hardness (annealed) ≤255 HB Not specified
Hardness (hardened) 58–62 HRC Not specified
Compressive Strength 2600 MPa Not specified
Typical Applications
AISI D2 KNL
Blanking dies, forming dies, thread rolling dies, punches, shear blades, gauges, broaches, drawing dies
BS 970 (Part 1) 709M40
Used for aircraft parts, heavy-duty gears, transmission shafts, connecting rods, crankshafts, and engineering fasteners.
Key Differences
Can AISI D2 KNL Be Substituted With BS 970 (Part 1) 709M40?
AISI D2 KNL and BS 970 (Part 1) 709M40 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
AISI D2 KNL
Round Bar → (2 listings)
Diameter: 80–80 mm (3.15–3.15 in)
Length: 2500–3600 mm (98.43–141.73 in)
BS 970 (Part 1) 709M40
Round Bar → (2 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 6600–6800 mm (259.84–267.72 in)
On M-EX Right Now
AISI D2 KNL
2 active listings and RFQs →
BS 970 (Part 1) 709M40
2 active listings and RFQs →
Frequently Asked Questions
What is the difference between AISI D2 KNL and BS 970 (Part 1) 709M40?
Different category: AISI D2 KNL is Tool & Die Steels, BS 970 (Part 1) 709M40 is Alloy Steel. AISI D2 KNL specifies Si, V, S, P which are not specified for BS 970 (Part 1) 709M40.
Can AISI D2 KNL be substituted with BS 970 (Part 1) 709M40?
AISI D2 KNL and BS 970 (Part 1) 709M40 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.