9. Comparison of pitch diameter tolerance Intro For Cutting Tap Unified Fine Thread (UNF) 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 P2 P3 3B 2BX 3B 905/16-24 UNF SL 2B 2B 121 GH2 GH3 GH4 GH5 1B 179 P1 P2 P3 PO 3B 2BX 3B 93 3/8-24 UNF 2B 2B 124 GH2 GH3 GH4 GH5 1B 187 P1 P2 P3 P4 ST 3B 2BX 3B 104 7/6-20 UNF 2B 2B 137 GH2 GH3 GH4 GH5 GH6 1B 205 ROLL P1 P2 P3 P4 3B 2BX 3B 106 1/2-20 UNF 2B 2B 141 GH2 GH3 GH4 GH5 GH6 1B 212 CARBIDE P1 P2 P3 P4 3B 2BX 3B 111 9/16-18 UNF 2B 2B 149 GH2 GH3 GH4 GH5 GH6 1B 225 LONG P1 P2 P3 P4 3B 2BX 3B 113 5/8-18 UNF 2B 2B 151 HAND GH2 GH3 GH4 GH5 GH6 1B 230 TAPS P2 P3 P4 3B 2BX 3B 124 3/4-16 UNF 2B 2B 164 EG (STI) GH3 GH4 GH5 GH6 1B 248 P2 P3 P43B2BX 3B 1347/8-14 UNF SPECIALTHREADS, 2B 2B 177 GAUGES GH3 GH4 GH5 GH6 GH7 1B 268 P2 P3 P4 THREAD 3B 2BX 3B 1441-12 UNF MILLS 2B 2B 192 GH3 GH4 GH5 GH6 GH7 1B 289 P2 P3 P4 DIES 3B 2BX 3B 149 1 1/8-12 UNF 2B 2B 197 GH3 GH5 GH7 1B 297 CENTER P2 P3 P4 DRILLS 3B 2BX 3B 152 1 1/4-12 UNF 2B 2B 203 GH3 GH5 GH7 1B 304 Technical info 655