It is used for inspecting the radial bound or end surface bound of columns,taper outer groove engaging gears and worm wheels and worms whose accuracy is at level 6 or below.

The radial bound of the gear ring Fr,within one rotation of the gear,the testing header is in the grooves or on the gear,and touch the both sides of the high and middle part of the groove,and the testing header shall point to the axle of the gear.