Bright cold finished bars (cold drawn, turned or precision ground) for general engineering purposes, in straight lengths; alloy case hardening steel (Table 15)
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Si
Mn
Cr
Ni
P
S
0.10-0.16
0.10-0.40
0.35-0.60
0.70-1.00
3.00-3.75
<=0.04
<=0.05
More data from BS 970 (Part 3):1991
From the standard
Other composition limits
Steel group
Alloy case hardening steel (Table 15)
Condition of supply
Bright bars: cold drawn, turned or precision ground, in straight lengths
Sulfur and phosphorus
S 0.05 max., P 0.04 max. for all qualities (Table 15, note a)
Maximum unless a range is stated.
Source: BS 970 (Part 3):1991, Table 15
Core properties by test bar diameter (blank carburized)
Test bar diameter (mm)
Tensile strength Rm, min (MPa)
Elongation, min (%)
Impact Izod, min (J)
Impact KCV, min (J)
19
1000
9
40
35
Mechanical tests are in the blank carburized condition (clause 7.3.3). The 19 mm test piece is to be used unless otherwise agreed (clause 10.4). See also option A.3.
Source: BS 970 (Part 3):1991, Table 22
Maximum hardness in the condition of delivery
Subcritically annealed, max
255 HB
Normalized and tempered, max
223 HB
Maximum hardness HB when specified on the order (note 14).
Source: BS 970 (Part 3):1991, Table 22
Heat treatment temperatures
Hardening temperature (case hardening)
800-820 deg C
Normalizing, hardening and tempering temperatures as given in Tables 27 and 28 (clause 4.2); Table 22 hardening temperatures for case hardening steels.
Source: BS 970 (Part 3):1991, Table 22
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