Carbide Sub Guide Posts

Carbide sub-guide posts are made of carbide (equivalent to V30) instead of high speed steel or high-carbon chromium bearing steel are generally used for an inner guide pins. Characteristics of carbide are superior to one of hard steel in terms of wear resistance, resistance to heat generation, and young modulus. Fig .2 shows characteristic of V30 (WC-Co) and high speed steel.

Improved Parts Precision, Minimized Clearance, and High Rigidity

Since the thermal expansion coefficient of the hard steel pins is high, the post diameter increases due to the high temperature by friction, resulting in increase in torque and heat generation. To prevent this, it is necessary to provide a large clearance between the post and bushing, resulting in poor positioning accuracy and variations in the precision of stamped parts. The thermal expansion coefficient of V30 is less than half that of high speed steel and the post diameter does not decrease. In addition, dimensional accuracy of each components (post and bushing) has been improved and the outer surface of the post is mirror-finished to attain both superb sliding performance and ultra-high rigidity. Therefore, the clearance between the post and bushing has been minimized, the positioning accuracy has been improved, and wear resistance and resistance to heat generation have been enhanced dramatically, assuring high precision and high rigidity over the long term.