Tung Pei has been established since 1966. We are the largest bearing manufacturer in Taiwan.

Ring Grinding


According to ISO 492:2002, TPI produces precision bearing in compliance with P4 class and we are capable to produce P2 level on request. The grinding machines are made from Germany (G&N、Peter Wolters、THIELENHAUS) and Japan (TOYO、SEIBU、DAISEI、TOHSHIN、NISSEI) specially designed for high precision and high rigidity. After grinding inner ring, we use automated inspection machine. Our manufacturing capability reaches Ppk 1.66 above and precision level control is using P2 level. The purpose is to make sure each bearing is made of P4 class and grinding precision for bearing can meet P2 class. 
Grinding process is set as automation so it can achieve stable quality output and environment is set with temperature control to avoid measurement deviation resulting from temperature difference. 


Spindle of a grinding machine for processing raceway of inner and outer rings for a bearing is with tens of thousands rpm. Precision is directly related to spindle vibration. Any minor unusual vibration will affect the precision after grinding. Therefore, we set surveillance system to monitor spindle vibration to assure production quality. This makes grinding process capability enhanced and yield rate for P4 class reaches 100%.

When grinding inner and outer rings, if the diameter of grinding wheel is too big, high speed rotation will result vibration which is because of uneven wheel mass. We installed dynamic balance system as standard equipment for grinding wheel. This minimizes wheel spindle vibration and reduces vibration trace when grinding raceway.