GUESSWORK:Use the 28-Piece Transfer Punches Set 3/32-Inch to 17/32-Inch to remove the guesswork of where to place the center punch mark in a hole when transferring dead center from threaded,drilled,tapped,and reamed holes;For toolmakers,machinists,fabricators,and hobbyists to use on metal,wood,and other surfaces;Useful for a tool for die marker or repair,finding stock screw and bolt hole locations,and even rock painting BUILT TO LAST:Constructed from heat-treated tempered steel with a black oxide finish for maximum strength and that resists and prevents rounding,mushrooming,or chipping of the conically-shaped(cone)tips;Flat ends are slightly chamfered at the edge;We recommend using these pieces as transfer punches-not intended to take place of a center punch EASY TO USE:Select one of the punches,hold punch shaft with one hand while gently tapping a hammer(not included)on the flat top of the punch to make a mark on your material that is visible for your center punch,then use your existing center punch(not included)to make a dimple Color:blue+black Material:plastic+metal Package Contents: 28* punching Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.