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BS 970 EN24 vs BS 970 (Part 3) 817M40

Strong Match — 92.5% match based on chemical composition and mechanical property overlap.

BS 970 EN24 (BS 970:1955) and BS 970 (Part 3) 817M40 (BS 970 (Part 3):1991) are both steel grades. Both fall under the Alloy Steel category. BS 970 EN24 is typically used for heavy duty gears, shafts, connecting rods, while BS 970 (Part 3) 817M40 is commonly used for high tensile shafts, gears, crankshafts. BS 970 EN24 is defined under British Standards (BS), originating from United Kingdom, while BS 970 (Part 3) 817M40 is defined under British Standards (BS), originating from United Kingdom.

As per chemical composition, BS 970 EN24 vs BS 970 (Part 3) 817M40 is a 92.5% 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 92.5%.

Frequently Compared With BS 970 EN24:
GOST 4543 12HN3A NF A35-565 100C6 UNI 11234 100Cr6 GB/T 3077 12Cr2Ni4A IS 1570 (Part 4) 105Cr5 IS 4367 07Cr4Mo6 IS 1570 (Part 4) 103Cr4 IS 1570 (Part 4) 10Cr20Mo6 IS 1570 (Part 7) 10Cr36Mo10H IS 1570 (Part 4) 07Cr4Mo6 IS 4367 10Cr9Mo10 IS 1570 (Part 4) 103Cr6
Match Breakdown
CHEMISTRY MATCH
92.5%
MECHANICAL MATCH
No shared data
OVERALL
92.5%
Specifications
Property BS 970 EN24 BS 970 (Part 3) 817M40
Standard BS 970:1955 BS 970 (Part 3):1991
Category Alloy Steel Alloy Steel
C (%) 0.35-0.45 0.36-0.44
Si (%) 0.10-0.35 0.10-0.40
Mn (%) 0.45-0.70 0.45-0.70
Ni (%) 1.30-1.80 1.30-1.70
Cr (%) 0.90-1.40 1.00-1.40
Mo (%) 0.20-0.35 0.20-0.35
S (%) <=0.050 <=0.040
P (%) <=0.050 <=0.035
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Mechanical Properties
Property BS 970 EN24 BS 970 (Part 3) 817M40
Tensile Strength ≥772 MPa (50 tons/sq in, converted) Not specified
Yield Strength ≥587 MPa (38 tons/sq in, converted) Not specified
Elongation ≥20% Not specified
Hardness 223-277 HB Not specified
Condition Hardened and tempered S, ruling section 6 in (lowest-strength condition of the standard) Not specified
Typical Applications
BS 970 EN24
Heavy duty gears, shafts, connecting rods
BS 970 (Part 3) 817M40
High tensile shafts, gears, crankshafts
Can BS 970 EN24 Be Substituted With BS 970 (Part 3) 817M40?
BS 970 EN24 and BS 970 (Part 3) 817M40 overlap closely enough on chemistry and mechanical properties that BS 970 (Part 3) 817M40 is often considered as a substitute for BS 970 EN24 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
BS 970 EN24
Round Bar → (26 listings)
Diameter: 50–130 mm (1.97–5.12 in)
Length: 4800–7000 mm (188.98–275.59 in)
Flat Bar → (6 listings)
Thickness: 25–40 mm (0.98–1.57 in)
Width: 200–200 mm (7.87–7.87 in)
Length: 2500–3900 mm (98.43–153.54 in)
Hex Bar → (4 listings)
Across Flats: 45–50 mm (1.77–1.97 in)
Length: 2500–3900 mm (98.43–153.54 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
BS 970 EN24
36 active listings and RFQs →
BS 970 (Part 3) 817M40
2 active listings and RFQs →
Frequently Asked Questions
What is the difference between BS 970 EN24 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 BS 970 EN24 be substituted with BS 970 (Part 3) 817M40?
BS 970 EN24 and BS 970 (Part 3) 817M40 overlap closely enough on chemistry and mechanical properties that BS 970 (Part 3) 817M40 is often considered as a substitute for BS 970 EN24 in many applications. Always confirm the specific property range your application needs before substituting, and check with your supplier's mill certificate.