HardLock Nut is constructed with two kinds of nuts, a convex nut with an eccentrically formed boss and a perfectly circular concave nut. When these nuts are fastened together,　“wedge principle”, ancient Japanese technology, mechanically creates a powerful locking effect transverse to the bolt shaft. This powerful anti-loosening effect completely integrates the bolt and the nut. Because of this, HLN is not susceptible to any impulsive forces or shocks. HLR series with rim has M5-M30, and HLB series of Bearing Nut has AN00-20.

A.P. Lock is the products from SUNGIL in Korea to fasten the shaft and the hub. SUNGIL supplies products made of various materials like S45C, electroless nickel plating, aluminum alloy and SIS304 at competitive price.