Bright cold finished bars (cold drawn, turned or precision ground) for general engineering purposes, in straight lengths; carbon and carbon manganese steel (Table 13)
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
P
S
0.32-0.40
0.10-0.40
1.30-1.70
<=0.05
<=0.05
More data from BS 970 (Part 3):1991
From the standard
Other composition limits
Steel group
Carbon and carbon manganese steel (Table 13)
Condition of supply
Bright bars: cold drawn, turned or precision ground, in straight lengths
Maximum unless a range is stated.
Source: BS 970 (Part 3):1991, Table 13
Mechanical properties by heat treatment condition
Condition
Reference symbol
Size (mm)
Tensile strength Rm (MPa)
Yield Re, min (MPa)
Elongation, min (%)
Impact Izod, min (J)
Impact KCV, min (J)
Rp0.2, min (MPa)
Hardness HB
Notes
Normalized + turned or ground
≥ 6 ≤ 150
620 min.
385
14
—
—
—
179-229
Normalized + turned or ground
> 150 ≤ 250
600 min.
355
15
—
—
—
170-223
Hardened and tempered + turned or ground
Q
> 19 ≤ 150
625-775
400
18
47
42
370
179-229
Hardened and tempered + turned or ground
R
> 13 ≤ 63
700-850
480
16
41
35
450
201-255
Hardened and tempered + turned or ground
S
≥ 6 ≤ 29
775-925
555
14
41
35
525
223-277
Hardened and tempered + turned or ground
T
≥ 6 ≤ 13
850-1000
635
12
34
28
620
248-302
(4)
Hardened and tempered + cold drawn or hardened and tempered + cold drawn + ground
Q
> 19 ≤ 150
625-775
440
13
47
—
400
179-229
Hardened and tempered + cold drawn or hardened and tempered + cold drawn + ground
R
> 13 ≤ 63
700-850
520
12
41
—
480
201-255
Hardened and tempered + cold drawn or hardened and tempered + cold drawn + ground
S
≥ 6 ≤ 29
775-925
580
10
41
—
540
223-277
Hardened and tempered + cold drawn or hardened and tempered + cold drawn + ground
T
≥ 6 ≤ 13
850-1000
665
9
34
—
635
248-302
(4)
Condition letters P to Z are the tensile strength ranges of Table 29. Rp0.2 applies when specifically ordered (note 3). Hardness HB is for guidance only except in the softened condition (note 13). Impact: Izod, or KCV when the standard impact test is not required (option A.3). Note 4: These properties cannot always be obtained by bulk heat treatment of bar but can be achieved by the appropriate heat treatment of components by the purchaser. Note 4: These properties cannot always be obtained by bulk heat treatment of bar but can be achieved by the appropriate heat treatment of components by the purchaser.
Source: BS 970 (Part 3):1991, Table 20
Heat treatment temperatures
Normalizing temperature
840-870 deg C
Hardening temperature
840-870 deg C, oil
Tempering temperature
550-660 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 27 and Table 28
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