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
Ni
Cr
S
P
<=0.15
>=0.20
<=2.00
7.0-10.0
17.0-20.0
<=0.045
<=0.045
Mechanical Properties
Tensile Strength
≥541 MPa (35 tons/sq in, converted)
Yield Strength
≥185 MPa (12 tons/sq in, converted)
Elongation
≥30%
Condition
, ruling section 6 in (lowest-strength condition of the standard)
More data from BS 970:1955
From the standard
Mechanical properties
Condition
Ruling section or size (in)
Tensile strength (tons/sq in)
Yield stress (tons/sq in)
Elongation (%)
Izod impact (ft lb)
Brinell (HB)
Proof stress 0.2% (tons/sq in), when requested
6
35
12
30
50
-
-
Values as printed in BS 970:1955; tensile strength, yield stress and proof stress in tons/sq in, Izod in ft lb. Minimum unless a range is shown.
Source: BS 970:1955, Part 2, En 58B (page 171)
Other tests and requirements
Ringing And Bend Test
Applies to En 58B, 58C, 58F, 58G, and to 58H and 58J when stabilised with titanium or niobium: test piece not larger than 1/2 in diameter or thickness; heated 30 minutes at 650 C, cooled in air, immersed 72 hours in boiling solution of 111 g copper sulphate (CuSO4.5H2O) and 98 g sulphuric acid (sp. gr. 1.84) made up to 1 litre with distilled water; then dropped on a metal or stone surface and must emit a clear metallic ring; then bent through 90 degrees over a radius of three times the diameter or thickness without cracking.
Source: BS 970:1955, Part 2, En 58B
Heat treatment
Soften
cooling freely in air or quenching in oil or water (at manufacturer option) from 950/1150 C
Temperatures in degrees C as printed.
Source: BS 970:1955, Part 2, En 58B (page 171)
Notes
Note
Ni plus Cr not less than 25.0 per cent; Ti not less than 4 times carbon content
Source: BS 970:1955, Part 2, En 58B
Status in the 1955 edition
Status
Deleted by Amendment 6
Reason
Amendment 6 (Feb 1970): stainless, heat resisting and valve steels moved to BS 970 Part 4:1970
BS 970:1955 was amended up to Amendment 10 (June 1972); steels were moved to the revised Parts 1 to 5 and deleted from this edition.
Source: BS 970:1955, Amendment slips 6 to 10
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