Thread Milling Tools UN INTERNAL ANSI B1.1 - 1982 UN NUT 1/4P 60 1/8P UN SCREW THREAD LENGTH – UP TO 2D D = NOMINAL THREAD SIZE THREAD SIZE PITCH ORDERING L L1 D1 D2 NO. OF TPI CODE FLUTES COARSE UNC FINE UNF 1 1-72 72 TMC03014L3 72UN 39 3.8 3 1.44 3 2 1-64 2-64 64 TMC03014L3 64UN 39 3.9 3 1.40 3 3 2-56 3-56 56 TMC03016L4 56UN 39 4.6 3 1.66 3 4 2-56 3-56 56 TMC06016L4 56UN 57 4.6 6 1.66 3 5 3-48 4-48 48 TMC06018L5 48UN 57 5.4 6 1.88 3 6 4-40 40 TMC06021L6 40UN 57 6.2 6 2.12 3 7 5-40 6-40 40 TMC06024L7 40UN 57 7.1 6 2.46 3 8 8-36 36 TMC06033L8 36UN 57 8.8 6 3.31 3 9 6-32 32 TMC06025L7 32UN 57 7.3 6 2.57 3 10 8-32 32 TMC06032L10 32UN 57 10.1 6 3.22 3 11 10-32 32 TMC06037L10 32UN 57 10.5 6 3.70 3 12 12-28 28 TMC06042L10 28UN 57 10.9 6 4.20 3 13 1/4"-28 28 TMC06052L14 28UN 57 14.0 6 5.20 3 14 10-24 24 TMC06035L10 24UN 57 10.4 6 3.55 3 15 5/16"-24 24 TMC08066L16 24UN 63 16.7 8 6.65 3 16 1/4"-20 7/16"-20 20 TMC06048L13 20UN 57 13.7 6 4.85 3 17 7/16"-20 20 TMC08079L24 20UN 63 24.0 8 7.95 3 18 5/16"-18 18 TMC06059L16 18UN 57 16.5 6 5.95 3 19 5/8"-18 18 TMC12119L34 18UN 84 34.0 12 11.90 4 20 3/8"-16 16 TMC08069L21 16UN 63 21.0 8 6.90 3 21 7/16"-14 14 TMC08079L23 14UN 63 23.5 8 7.95 3 22 1/2"-13 13 TMC10093L27 13UN 73 27.0 10 9.30 3 23 9/16"-12 12 TMC10099L29 12UN 63 29.0 10 9.95 3 24 5/8"-11 11 TMC12115L33 11UN 84 33.0 12 11.50 3 16