Quickly and accurately measures pitch diameters of external threads-a must-have when cutting or checking threads on precision screws. Accurate to within +/- .0001" along the center 1" section. Measures the following pitch sizes: 3 to 48 tpi, .5mm to 6mm pitch, and Acme 3 to 16 tpi. Includes plastic storage sleeve, conversion chart and instructions. Requires micrometer, not included. Mfg: Fisher Machine Shop SPECS: Steel, 2A 3/4" (7cm) OAL. Contains 16 different wire sizes, (3) of each diameter: .018" (.45mm), .024" (.61mm); .029" (.74mm), .032" (.81mm), .040" (1mm); .045" (1.1mm), .055" (1.4mm), .063" (1.6mm), .072" (1.8mm), .081" (2.1mm), .092&