BS 970 EN31 vs BS 970 (Part 1) 535A99

Close Alternative — 83.8% match based on chemical composition and mechanical property overlap.

BS 970 EN31 (BS 970:1955) and BS 970 (Part 1) 535A99 (BS 970 (Part 1):1983) are both steel grades. Both fall under the Alloy Steel category. BS 970 EN31 is typically used for ball and roller bearings, gauges, dies, while BS 970 (Part 1) 535A99 is commonly used for used for aircraft fittings, gears, high-strength shafts, crankshafts, heavy-duty fasteners, and transmission parts.. BS 970 EN31 is defined under British Standards (BS), originating from United Kingdom, while BS 970 (Part 1) 535A99 is defined under British Standards (BS), originating from United Kingdom.

As per chemical composition, BS 970 EN31 vs BS 970 (Part 1) 535A99 is a 83.8% 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 83.8%.

Frequently Compared With BS 970 EN31:
UNI 11234 100Cr6 NF A35-565 100C6 GB/T 3077 12Cr2Ni4A IS 1570 (Part 4) 103Cr4 IS 1570 (Part 4) 103Cr6 IS 1570 (Part 4) 105Cr5 GOST 4543 12HN3A IS 4367 07Cr4Mo6 IS 1570 (Part 4) 07Cr4Mo6 IS 1570 (Part 7) 10Cr36Mo10H IS 1570 (Part 4) 10Cr20Mo6 EN 10028-2 10CrMo9-10
Match Breakdown
CHEMISTRY MATCH
83.8%
MECHANICAL MATCH
No shared data
OVERALL
83.8%
Specifications
Property BS 970 EN31 BS 970 (Part 1) 535A99
Standard BS 970:1955 BS 970 (Part 1):1983
Category Alloy Steel Alloy Steel
C (%) 0.90-1.20 0.95-1.10
Si (%) 0.10-0.35 Not specified
Mn (%) 0.30-0.75 0.40-0.70
Cr (%) 1.00-1.60 1.20-1.60
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 EN31 BS 970 (Part 1) 535A99
Hardness (HB) ≤229 (softened) Not specified
Typical Applications
BS 970 EN31
Ball and roller bearings, gauges, dies
BS 970 (Part 1) 535A99
Used for aircraft fittings, gears, high-strength shafts, crankshafts, heavy-duty fasteners, and transmission parts.
Key Differences
Can BS 970 EN31 Be Substituted With BS 970 (Part 1) 535A99?
BS 970 EN31 and BS 970 (Part 1) 535A99 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
BS 970 EN31
Round Bar → (23 listings)
Diameter: 40–50 mm (1.57–1.97 in)
Length: 2500–7000 mm (98.43–275.59 in)
Flat Bar → (3 listings)
Thickness: 25–25 mm (0.98–0.98 in)
Width: 120–120 mm (4.72–4.72 in)
Length: 2500–3600 mm (98.43–141.73 in)
Hex Bar → (3 listings)
Across Flats: 50–50 mm (1.97–1.97 in)
Length: 2600–3300 mm (102.36–129.92 in)
BS 970 (Part 1) 535A99
Round Bar → (2 listings)
Diameter: 50–50 mm (1.97–1.97 in)
Length: 5200–6400 mm (204.72–251.97 in)
On M-EX Right Now
BS 970 EN31
29 active listings and RFQs →
BS 970 (Part 1) 535A99
2 active listings and RFQs →
Frequently Asked Questions
What is the difference between BS 970 EN31 and BS 970 (Part 1) 535A99?
BS 970 EN31 specifies Si which is not specified for BS 970 (Part 1) 535A99.
Can BS 970 EN31 be substituted with BS 970 (Part 1) 535A99?
BS 970 EN31 and BS 970 (Part 1) 535A99 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.