Thread Milling Tools NPT INTERNAL / EXTERNAL ANSI/ASME B 1.20.1-1983 NPT NUT 30 30 90 1 47 NPT SCREW NPT SCREW HELICAL FLUTES THREAD PITCH ORDERING L L1 D1 D2 NO. OF SIZE TPI CODE FLUTES 1 1/16" 27 TMG06059L09 27NPT 57 9.8 6 5.9 3 2 1/8" 27 TMG08077L10 27NPT 63 10.9 8 7.7 3 3 1/4"-3/8" 18 TMG10099L16 18NPT 73 16.4 10 9.9 4 4 1/2" 14 TMG12119L20 14NPT 84 20.8 12 11.9 4 5 1/2" 14 TMG16159L20 14NPT 93 20.8 16 15.9 4 6 1"-2" 11.5 TMG20199L29 11.5NPT 105 29.7 20 19.9 4 7 2 1/2"-6" 8 TMG20199L38 8NPT 105 38.1 20 19.9 4 HELICAL FLUTES WITH COOLANT HOLE THREAD PITCH ORDERING L L1 D1 D2 NO. OF SIZE TPI CODE FLUTES 1 1/16" 27 TMGB06059L09 27NPT 57 9.8 6 5.9 3 2 1/8" 27 TMGB08077L10 27NPT 63 10.9 8 7.7 3 3 1/4"-3/8" 18 TMGB10099L16 18NPT 73 16.4 10 9.9 4 4 1/2" 14 TMGB12119L20 14NPT 84 20.8 12 11.9 4 5 1/2" 14 TMGB16159L20 14NPT 93 20.8 16 15.9 4 6 1"-2" 11.5 TMGB20199L29 11.5NPT 105 29.7 20 19.9 4 7 2 1/2"-6" 8 TMGB20199L38 8NPT 105 38.1 20 19.9 4 9