Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Mn
0.07-0.13
0.30-0.60
Mechanical Properties
Condition
Case hardened, 19 mm test bar
Tensile Strength
430 MPa min
Elongation
18 % min
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 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
430
18
35
42
19 (preferred size)
430
18
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
Heat treatment
Hardening temperature
900-930 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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