Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Mn
Cr
Mo
Ni
0.14-0.20
0.70-1.05
0.35-0.65
0.30-0.40
0.35-0.75
More data from BS 970 (Part 1):1991
From the standard
Other composition limits
Category
Category 1 steel
Category 1 steels are preferred for new designs and established designs (clauses 1.4 and 2.1). Category 2 steels are printed in italic type.
Source: BS 970 (Part 1):1991, Table 7
Hardenability, end quench testHardness band
Hardness band (HRC, minimum to maximum) by distance from the quenched end (mm)
1.5
3
5
7
9
11
13
15
20
25
30
35
40
45
Distance from quenched end (mm)
1.5
3
5
7
9
11
13
15
20
25
30
35
40
45
Maximum, HRC
46
45
44
41
38
34
32
30
28
27
26
26
25
25
Minimum, HRC
39
38
33
27
24
23
21
21
19
18
H grade requirement for case hardening steels; see also the curves in Appendix A, which are for guidance only.
Source: BS 970 (Part 1):1991, Table 7
Heat treatment
Preheat treatment temperature, hardenability test
930-950 deg C
Austenitizing temperature, hardenability test
925 deg C
Table 9: heat treatment of case hardening steels. Values as printed; a dash in the table means not specified.
Source: BS 970 (Part 1):1991, Table 9
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