IS 1570 (Part 2/Sec 1):1979 20C8 Steel: Specifications & Listings
IS 1570 (Part 2/Sec 1):1979 20C8: Unalloyed carbon steel designated 20C8 in IS 1570 (Part 2/Sec 1):1979, with carbon 0.15-0.25% and manganese 0.60-0.90%. Old designation C20. The standard was reaffirmed in 2004.
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
C
Mn
0.15-0.25
0.60-0.90
Mechanical Properties
Tensile Strength
440-520 MPa
Elongation
>=24%
More data from IS 1570 (Part 2/Sec 1):1979
From the standard
Cold-drawn bars, tensile by size4 size ranges
Size (mm)
Tensile strength, min (MPa)
Elongation, min (%)
Up to 20
540
10
Over 20 to 40
510
12
Over 40 to 63
470
15
Over 63
430
18
Source: IS 1570 (Part 2/Sec 1):1979, Edition 2.1 (Amendment 1, December 1989), Table 3
Core properties after case hardeningrefined and quenched
Tensile strength, min (MPa)
Elongation, min (%)
Izod impact, min (J)
Limiting ruling section (mm)
500
16
55
30
Properties in the core of case-hardened parts after refining and quenching. Impact value applies when specified.
Source: IS 1570 (Part 2/Sec 1):1979, Edition 2.1 (Amendment 1, December 1989), Table 5
Mild steel sheet and strip1 condition
Condition
Tensile strength (MPa)
Elongation, min (%)
Cold rolled and annealed
390 to 510
25
Elongation on a test piece 12.5 mm wide, gauge length 50 mm.
Source: IS 1570 (Part 2/Sec 1):1979, Edition 2.1 (Amendment 1, December 1989), Table 6
Tubes, cold drawn2 conditions
Condition
Tensile strength, min (MPa)
Yield stress, min (MPa)
Cold drawn and annealed
370
220
Cold drawn, or cold drawn and tempered
520
42
Elongation, min: 950 divided by the actual tensile strength in kgf/mm² on a gauge length of 5.65 times the square root of the cross-section, or 1100 divided by it on 4 times the square root. Table 8 of the standard prints this yield stress as 42 under MPa; it appears to be in kgf/mm², about 412 MPa.
Source: IS 1570 (Part 2/Sec 1):1979, Edition 2.1 (Amendment 1, December 1989), Table 8
Active IS 1570 (Part 2/Sec 1):1979 20C8 Listings on M-EX (For Sale)