◎A combination of high precision bronze / nickel worm wheel and case hardened steel worm screw ensures long term indexing accuracy. ◎ Dual lead worm wheel/worm shaft which allowable easy backlash adjustmen. ◎ Double bearing design suitable for heavy cutting. ◎ One piece of faceplate and spindle design which offer rigid construction. ◎ Low Gear ratio design (90:1) which offer high speed feed rate. ◎ Large thru hole design which allowable large work piece going thru spindle.