IS 11169 (Part 1):2022 23C8BT Steel: Specifications & Listings
IS 11169 (Part 1):2022 23C8BT: Cold heading quality boron alloyed steel 23C8BT to IS 11169 (Part 1):2022 for quenching and tempering after cold heading or cold extrusion, supplied as wire rod, bars or wire of 2 to 100 mm. Maximum tensile strength annealed is 490 MPa. It can be ordered with hardenability requirements (H, CH).
Cold heading and cold extrusion of parts that are quenched and tempered; the standard covers bars, wire rods and wires of 2 to 100 mm (clause 1.1, Annex C)
Matched by chemical composition and mechanical properties, not a formal equivalence claim. Always verify against the applicable standard before substitution.
Chemical Composition (%)
B
C
Cr
Cu
Mn
P
S
Si
0.0008-0.005
0.20-0.25
<=0.30
<=0.25
0.60-0.90
<=0.025
<=0.025
<=0.30
Mechanical Properties
Core Hardness (CH)
>=40 HRC up to 9 mm
Tensile Strength, annealed (+AC)
<=490 MPa (over 5 to 25 mm)
More data from IS 11169 (Part 1):2022
From the standard
Other composition limitsfrom the table notes and clauses
Values
Maximum unless a range is given (ladle analysis)
Silicon
Lower silicon contents may be agreed when ordering, with due regard to the effect on properties such as hardenability
Chromium
Where a maximum of 0.30 percent is specified, a minimum may also be agreed when ordering
Aluminium
0.020 to 0.050 percent may be added to improve cold heading
Ordered with hardenability
Small deviations from these limits are allowed (not for sulphur and phosphorus): up to 0.01 percent for carbon and the Table 1 values for other elements
Deoxidation
Aluminium killed (clause 6.2)
Elements not listed are not added intentionally without the purchaser's agreement, except those used to finish the heat.
Source: IS 11169 (Part 1):2022, Table C.3 and its notes, clause 6.2
Tensile strength and reduction of area by delivery conditionby delivery condition and size
Delivery condition
Diameter (mm)
Tensile strength, max (MPa)
Reduction of area, min (%)
+AR or +PE
over 5 to 10
600
60
+AR or +PE
over 10 to 25
600
60
+AC or +AC+PE
over 5 to 10
490
66
+AC or +AC+PE
over 10 to 25
490
66
+AR+C
over 5 to 10
690
55
+AR+C
over 10 to 25
680
55
+AR+C+AC
2 (incl.) to 5
480
68
+AR+C+AC
over 5 to 10
470
68
+AR+C+AC
over 10 to 25
470
68
+AR+C+AC+LC
2 (incl.) to 5
520
66
+AR+C+AC+LC
over 5 to 10
510
66
+AR+C+AC+LC
over 10 to 25
510
66
+AC+C
over 5 to 10
580
61
+AC+C
over 10 to 25
570
61
Codes: +AR as hot rolled, +PE peeled, +C cold drawn, +AC annealed to spheroidized carbides, +LC skin passed. For non-circular sections the properties are agreed between manufacturer and purchaser. In the +AR condition the tensile values do not suit the whole composition range; take care that they match the hardenability needs. Table C.7 heads the last reduction of area column as maximum; shown here as minimum.
Source: IS 11169 (Part 1):2022, Table C.7
Hardenability, end quench test (H)Hardness band
Hardness band (HRC, minimum to maximum) by distance from the quenched end (mm)
1.5
3
5
7
9
11
13
15
20
25
30
35
40
45
50
Distance from quenched end (mm)
1.5
3
5
7
9
11
13
15
20
25
30
35
40
45
50
Maximum, HRC
49
48
47
45
39
-
-
-
-
-
-
-
-
-
-
Minimum, HRC
41
39
37
21
-
-
-
-
-
-
-
-
-
-
-
Applies when ordered with the symbol H; otherwise for guidance only. Jominy test as per IS 3848, austenitizing at 890 ± 5 °C.
Source: IS 11169 (Part 1):2022, Table C.10
Core hardening (CH)CH ordering
Austenitizing temperature
890 °C ± 5
Minimum core hardness, 90 percent martensite
40 HRC
Maximum diameter for 90 percent martensite in the core
9 mm
Applies when ordered with the symbol CH. The diameter is the one reached with the lowest hardenability of the grade; HH grades allow a larger diameter. A hardening time of at least 30 minutes at temperature is recommended.
Source: IS 11169 (Part 1):2022, Table C.12, clauses 8.2.4 and 8.2.6
Active IS 11169 (Part 1):2022 23C8BT Listings on M-EX (For Sale)