BS 970 (Part 1):1983 135M44: 135M44 is a carbon manganese steel grade specified in BS 970 Part 1:1983 (Table 6, category 1). Section three of the standard advises that category 1 steels be used for new designs and established designs whenever possible.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Mn
P
S
0.40-0.48
1.20-1.50
<=0.050
<=0.050
More data from BS 970 (Part 1):1983
From the standard
Other composition limits
Phosphorus and sulphur
Each 0.050 max (clause 1.7.2.1, carbon and carbon manganese steels)
Residual elements: see clause 1.7.3.
Source: BS 970 (Part 1):1983, Table 6
Heat treatment and maximum hardness (through hardening)
Hardening temperature
830-860 deg C
Quenching medium
Oil
Tempering temperature
550-660 deg C
Hardenability test
No hardenability data specified
Softened condition
Not usually supplied in the softened condition
Heat treatment to be given to test bars and to material required in the finally heat treated condition. Note 24: O = oil, W = water. Where oil hardening is specified, either a well-agitated conventional oil or a proven synthetic quenchant may be used. Synthetic quenchants shall not be used for the heat treatment of test bars for material not supplied in the finally heat treated condition.
Source: BS 970 (Part 1):1983, Table 7
Mechanical properties by heat treatment condition
Condition
Limiting ruling section (mm)
Rm (N/mm2)
Re min (N/mm2)
A min (%)
Izod min (ft lbf)
KCV min (J)
Rp0.2 min (N/mm2), when specifically ordered
HB
Q
150
625-775
415
16
35
42
385
179-229
R
100
700-850
490
15
30
35
460
201-255
S
29
775-925
580
14
30
35
550
223-277
T (note 13)
19
850-1000
650
12
25
28
620
248-302
U (note 13)
13
925-1075
700
10
20
22
670
269-331
Values as printed in Table 6 for the limiting ruling section shown. Rp0.2 applies when specifically ordered (note 10). 1 N/mm2 = 1 MPa. Note 13: may not always be obtained by bulk heat treatment, but the properties can be achieved by the appropriate heat treatment of die forgings and components, and also apply to test bars.
Source: BS 970 (Part 1):1983, Table 6
Comparison with earlier editions
BS 970:1970/72 designation
Not listed
BS 970:1955 En No.
None
Appendix D note 47: where a comparison is made the steels are not necessarily equivalent. 'Not listed' means the earlier edition has no entry under this designation.
Source: BS 970 (Part 1):1983, Appendix D
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