Main roller is the shaft to rotate in high speed with large weight and, accordingly, high rigidity, high balance and high precision machining skills are needed while being produced.

Grooving, which is the most important part in main roller processing, is conducted on the CNC Lathe of LB400 Model adopted from OKUMA, the Japanese precision machine tool maker. With the perfection of 5㎛ pitch interval, the processing is followed by washing, surface measurement and packaging with the measurement data. The products are finally delivered to Komatsu- NTC.