Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Mn
0.13-0.18
1.10-1.40
Mechanical Properties
Condition
Case hardened, 19 mm test bar
Tensile Strength
650 MPa min
Elongation
14 % min
More data from BS 970 (Part 1):1991
From the standard
Other composition limits
Category
Category 2 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 8
Core properties after case hardening, by test bar diameter
Test bar diameter (mm)
Tensile strength, min (MPa)
Elongation, min (%)
Impact Izod, min (ft lb)
Impact KCV, min (J)
13
740
13
25
28
19 (preferred size)
650
14
30
35
29
590
15
35
42
Properties of simulated case hardened test bars (clause 1.13.3.4). 1 N/mm2 = 1 MPa. Note 29: these are new steels which may have been conservatively rated due to limited data.
Source: BS 970 (Part 1):1991, Table 8
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