To obtain smaller and higher-quality small-diameter seamless steel pipes, cold rolling, cold drawing, or a combination of both methods must be used. Cold rolling is typically performed on a two-roll mill, where the steel pipe is rolled in an annular die formed by a variable cross-section circular groove and a stationary conical mandrel. Cold drawing is usually performed on single-chain or double-chain cold drawing machines with a capacity of 0.5–100T.
Cold-drawn seamless steel pipes are high-precision steel pipe materials manufactured through a cold drawing process. They feature high dimensional accuracy, good surface finish, and excellent mechanical properties, and are mainly used in hydraulic systems, transmission components, and other mechanical manufacturing fields.
High-quality carbon structural steel cold-drawn seamless pipes are mainly manufactured using No. 10, No. 20, No. 35, and No. 45 steel. In addition to ensuring chemical composition and mechanical properties, they undergo hydrostatic testing, flanging, flaring, and flattening tests.
The formula for calculating the weight of cold-drawn seamless steel pipes is: (Outer diameter - Wall thickness) * Wall thickness * 0.02466 = kg/meter (weight per meter).
