9. Comparison of pitch diameter tolerance Intro For Cutting Tap Unified Coarse Thread (UNC) Basic Pitch (+) μm SP Dia. 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 P1 3B 3B 47No.1-64 UNC SL 2B 2B 65 GH1 GH2 P1 3B 2BX PO 3B 3B 53 No.2-56 UNC 2B 2B 70 2B GH1 GH2 Internal threads 3B Internal threads 2B P1 Internal threads 1B ST 3B 3B 55 No.3-48 UNC 2B 2B 75 GH1 GH2 ROLL P1 P2 P3 3B 2BX 3B 60 No.4-40 UNC 2B 2B 83 GH2 GH3 GH4 CARBIDE P1 P2 3B 3B 63 No.5-40 UNC 2B 2B 83 GH2 GH3 LONG P1 P2 P3 3B 2BX 3B 68 No.6-32 UNC 2B 2B 93 HAND GH2 GH3 GH4 GH5 TAPS P1 P2 P3 3B 2BX 3B 71 No.8-32 UNC 2B 2B 96 EG (STI) GH2 GH3 GH4 GH5 P1 P2 P33B2BX 3B 80No.10-24 UNC SPECIALTHREADS, 2B 2B 108 GAUGES GH2 GH3 GH4 GH5 P1 P2 P3 THREAD 3B 2BX 3B 82No.12-24 UNC MILLS 2B 2B 110 GH2 GH3 GH4 GH5 P1 P2 P3 DIES 3B 2BX 3B 90 1/4-20 UNC 2B 2B 123 GH2 GH3 GH5 1B 184 CENTER P2 P3 DRILLS 3B 2BX 3B 98 5/16-18 UNC 2B 2B 134 GH2 GH3 GH5 1B 200 Technical info 651