After the valve ball and the valve seat are hardened, they need to go through the process of grinding and polishing. The ball used in the valve ball has manual grinding and mechanical grinding. Manual grinding is generally the first file, sandpaper to be filleted to be studied on the surface of the ball valve, and then with the appropriate abrasive sand on the valve ball and valve seat manual research, mechanical grinding is mainly the use of special machine or modified machine for grinding operation.

However, manual grinding and mechanical grinding only applies to the surface hardness of less than 60HRC and roundness tolerance of less than 011mm ball, and the production efficiency is relatively low, labor intensity required. Spheres that have been surface treated with supersonic or super-hard spray techniques have a surface hardness of 65 to 70 HRC and a roundness tolerance of more than 0.01 mm, making them impossible to machine.