Seamless steel tubes are round, square and rectangular steel with hollow section and no welded seam. The tubes are manufactured through an extrusion process where the tube is drawn from a steel ingots or solid tube billet and extruded into a hollow form. Tubing is further shaped hot rolling process, cold rolling process or cold drawing process.

The heat treatment of steel is to change the internal structure of the steel through heating, heat preservation and cooling in a solid state, thereby changing the mechanical properties of the steel. Common heat treatment methods include quenching, tempering, normalizing, annealing, and tempering.

Aluminum alloy is the most widely used non-ferrous metal structural material in industry. It has been widely used in aviation, aerospace, automobile, machinery manufacturing, shipbuilding and chemical industries.

Induction annealing is a special heat treatment process, heating the metal or alloy to an appropriate temperature, holding it for a certain period of time, and then slowly cooling.

Ball studs are widely used in independent suspension systems. Control arms or thrust rods are often connected to other components through ball studs at the end.

Bearings are used for automobiles, sliding bearings are mainly used in engines. rolling bearings are widely used in various mechanical and electrical assemblies in automobiles.