Post Stock Login Register

NF A35-552 40NCD3 vs BS 970 (Part 3) 817M40

Close Alternative — 73.9% match based on chemical composition and mechanical property overlap.

NF A35-552 40NCD3 (NF A35-552:1986) and BS 970 (Part 3) 817M40 (BS 970 (Part 3):1991) are both steel grades. Both fall under the Alloy Steel category. NF A35-552 40NCD3 is typically used for used for gears, aircraft fittings, transmission shafts, crankshafts, heavy-duty bolts, and connecting rods., while BS 970 (Part 3) 817M40 is commonly used for high tensile shafts, gears, crankshafts. NF A35-552 40NCD3 is defined under Association Francaise de Normalisation (NF), originating from France, while BS 970 (Part 3) 817M40 is defined under British Standards (BS), originating from United Kingdom.

As per chemical composition, NF A35-552 40NCD3 vs BS 970 (Part 3) 817M40 is a 73.9% 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 73.9%.

Frequently Compared With NF A35-552 40NCD3:
GOST 4543 12HN3A NF A35-565 100C6 UNI 11234 100Cr6 GB/T 3077 12Cr2Ni4A IS 4367 07Cr4Mo6 IS 1570 (Part 4) 07Cr4Mo6 IS 1570 (Part 4) 103Cr4 IS 1570 (Part 7) 10Cr36Mo10H IS 1570 (Part 4) 103Cr6 IS 1570 (Part 4) 105Cr5 IS 1570 (Part 4) 10Cr20Mo6 IS 4367 10Cr9Mo10
Match Breakdown
CHEMISTRY MATCH
73.9%
MECHANICAL MATCH
No shared data
OVERALL
73.9%
Specifications
Property NF A35-552 40NCD3 BS 970 (Part 3) 817M40
Standard NF A35-552:1986 BS 970 (Part 3):1991
Category Alloy Steel Alloy Steel
C (%) 0.37-0.43 0.36-0.44
Si (%) 0.15-0.40 0.10-0.40
Mn (%) 0.50-0.80 0.45-0.70
Ni (%) 1.00-1.40 1.30-1.70
Cr (%) 0.60-1.00 1.00-1.40
Mo (%) 0.15-0.30 0.20-0.35
P (%) 0.035 max <=0.035
S (%) 0.035 max <=0.040
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property NF A35-552 40NCD3 BS 970 (Part 3) 817M40
Tensile Strength 850-1050 MPa Not specified
Yield Strength 650-850 MPa Not specified
Elongation 10-15% Not specified
Hardness 250-320 HB Not specified
Typical Applications
NF A35-552 40NCD3
Used for gears, aircraft fittings, transmission shafts, crankshafts, heavy-duty bolts, and connecting rods.
BS 970 (Part 3) 817M40
High tensile shafts, gears, crankshafts
Can NF A35-552 40NCD3 Be Substituted With BS 970 (Part 3) 817M40?
NF A35-552 40NCD3 and BS 970 (Part 3) 817M40 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
NF A35-552 40NCD3
Round Bar → (2 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 6500–6600 mm (255.91–259.84 in)
BS 970 (Part 3) 817M40
Round Bar → (2 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 6200–6500 mm (244.09–255.91 in)
On M-EX Right Now
NF A35-552 40NCD3
2 active listings and RFQs →
BS 970 (Part 3) 817M40
2 active listings and RFQs →
Frequently Asked Questions
What is the difference between NF A35-552 40NCD3 and BS 970 (Part 3) 817M40?
Both grades share a similar composition profile; see the specification table above for the exact chemistry and mechanical property values.
Can NF A35-552 40NCD3 be substituted with BS 970 (Part 3) 817M40?
NF A35-552 40NCD3 and BS 970 (Part 3) 817M40 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.