45# seamless steel tube is a high-quality carbon structural steel with low hardness and easy cutting processing. It is commonly used in molds as templates, tips, guide posts, etc., but requires heat treatment.

The average carbon content of 45# seamless steel tube is 0.42-0.50%, the average silicon content is 0.17-0.37%, the average manganese content is 0.50-0.80%, the average sulfur content is <=0.035%, and the average phosphorus content is <= 0.035%, average chromium content<=0.25%, average nickel content<=0.30%, average copper content<=0.25%,

45# seamless steel tube tensile strength ≥ 590Mpa, elongation ≥ 14%.

45# seamless steel tube is called in the national standard GB. It is called S45C in the Japanese standard JIS, 1045 in the American standard ASTM, and is called C45 in the German DIN.

45# seamless steel tube is widely used in machinery manufacturing, and the mechanical properties of 45# seamless steel tube are very good. But 45# seamless steel tube is a kind of medium carbon steel, the quenching performance is not good, 45# seamless steel tube can be quenched to HRC42~46. Therefore, if the surface hardness is required and the superior mechanical properties of the 45# seamless steel tube are desired, the surface of the 45# seamless steel tube is often carburized and quenched to obtain the required surface hardness.