B-29BMitutoyo operates a policy of continuous improvement that aims to provide the customer with the benet of the latest technological advances.Therefore the company reserves the right to change any or all aspects of any product specication without notice.MicrometerThe origin of Mitutoyo’s trustworthy brand of small tool instruments3-Wire UnitsSERIES 313 • Enables measurement of the pitch diameter of screw threads with a standard micrometer. • Determination of the pitch diameter: refer to “Quick Guide to Precision Measuring Instruments”.Order No.(One pair)(Support spindle dia.)ø6.35mm (.25"DIA.)Wire dia.(mm)PitchMetric thread(mm)Unied thread(thread per inch)Whitworth thread (thread per inch)9521310.1700.2, 0.25, 0.380—9521320.1950.3572—9521330.2200.464—9521340.2500.4556609521350.2900.548489521360.3350.644, 40409521370.3900.736369521380.4550.75, 0.832329521390.5300.92828, 269521400.6201.02424, 229521410.7251.252020, 19, 189521420.8951.518, 16169521431.1001.75, 2.014, 13, 1214, 129521441.3502.511, 1011, 109521451.6503.09, 89, 89521462.0503.5779521472.5504, 4.5669521483.2005, 5.5, 65, 4.55, 4.5SPECIFICATIONS3-Wire Units setOrder No.SetWire dia. (mm)Support spindle dia. (mm)313-101180.170 - 3.200ø6.35Technical DataAccuracy of wire diameter: ±2μm952141


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