The shorter length provides extra rigidity and strength in tough materials. They are ideal for Bridgeport, and hand-held applications. Diameter Tollerances: -.0000” -.000m/m, + .0003” -.008m/m, +.0001” +.0025m/m, +.0005” +.012m/m. Contains 1 piece of each: 5/8", 11/16", 3/4", 13/16", 7/8", 1".