IS 11169 (Part 1):2022 21C10BT Steel: Specifications & Listings
IS 11169 (Part 1):2022 21C10BT: Cold heading quality boron alloyed steel 21C10BT 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 hardness in the annealed condition is 160 HBW. It can be ordered with hardenability requirements (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
Mo
P
S
Si
0.0005-0.003
0.18-0.23
<=0.15
<=0.15
0.80-1.10
<=0.05
<=0.035
<=0.035
0.15-0.30
Mechanical Properties
Core Hardness (CH)
>=40 HRC up to 12 mm
Hardness, annealed (+AC)
<=160 HBW
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)
Residual elements, maximum
Sn 0.020, V 0.05 percent; Cr + Ni + Cu + Sn + Mo + V together not over 0.40 percent, where not used as alloying elements
Aluminium
0.020 to 0.050 percent may be added to improve cold heading
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
Hardness in the annealed condition1 condition
Annealed (+AC), maximum
160 HBW
Brinell hardness for products delivered in the annealed condition.
Source: IS 11169 (Part 1):2022, Table C.8, clause 8.1
Core hardening (CH)CH ordering
Austenitizing temperature
880 °C ± 5
Minimum core hardness, 90 percent martensite
40 HRC
Maximum diameter for 90 percent martensite in the core
12 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 21C10BT Listings on M-EX (For Sale)