1.1 This standard covers the requirements of the following types of chrome molybdenum steel, seamless, boiler and superheater tubes:
a) Cold drawn seamless 1 percent chromium and 1/2 percent molyb-denum steel tubes (see Section 2) ;
b) Hot finished seamless 1 percent chromium and 1/2 percent molyb-denum steel tubes (see Section 3);
c) Cold 'drawn seamless 21/4 percent chromium and 1 percent molyb-denum steel tubes (see Section 4); and
d) Hot finished seamless 21/4 percent chromium and 1 percent molyb-denum steel tubes (see Section 5).
1.2 Details of the grades of tubes and materials dealt with under each type are given in subsequent sections.
IS 3609-1966 history
1967IS 3609-1966 Specification for chromium-molybdenum steel, seamless boiler tubes and superheater tubes