A tolerance is specified in the manufacturing process of any product, and what is the tolerance for the thick-walled cylindrical steel tubes we commonly use?

In daily applications, the common tolerance of thick-walled cylinder steel tubes is generally g6 or h7, and the chrome plating thickness ranges from 0.8 to 3 mm. Grade A3 steel was a former designation; it is now called Q235 steel, with a yield strength of 235 MPa, a tensile strength of 375–460 MPa, and an elongation of 26%. In carbon steel plates, Q235 is the most common material and belongs to the general-purpose carbon steel plate series.

Thick-walled cylindrical steel tubes of Grade 45 are made of high-quality carbon steel, with a tensile strength of ≥600 MPa and a yield strength of ≥355 MPa. Q235 is a low-carbon steel with excellent weldability. Grade 45 steel is a medium-carbon steel with poor weldability; it is generally used to manufacture shaft parts and other components, and heat treatment is required to improve its mechanical properties.

The above is an introduction to the tolerances of thick-walled cylindrical steel tubes.