Used for grinding and setting screw cutting tools. Scales with 14ths and 20ths graduations provided on one side, 24ths and 32nds on reverse side. Scales are used to determine number of threads per inch. Gage also features a table of double depths of thread for selecting size of tap drills. Made of hardened spring tempered steel, with a protective satin chrome finish. All gaging surfaces are precision ground.