14. Tap, Thread Limits Production data ■ for Helical Coil Wire Thread Inserts, Metric Threads unit: mm ■ for Helical Coil Wire Thread Inserts, Unified Threads unit: mm Major Pitch Diameter Minor Major Pitch Diameter Minor Diameter Diameter Diameter Diameter Size Class Upper Lower Size Class Upper Lower Basic Size Basic Size Tolerance Tolerance Basic Size Basic Size Basic Size Tolerance Tolerance Basic Size (μm) (μm) (μm) (μm) + + + + STI M 2.6 × 0.45 b 3.185 2.892 18 6 2.698 b 18 6 STI No. 2 - 56 UNC 2.773 2.479 2.283 b 18 6 GH2 25.4 12.7 STI M 3 × 0.5 3.650 3.324 3.108 G3 38 25 b 18 6 STI No. 4 - 40 UNC 3.670 3.258 2.981 b 18 6 GH2 25.4 12.7 STI M 4 × 0.7 4.909 4.454 4.151 G4 51 38 STI No. 4 - 48 UNF b 3.532 3.189 18 6 2.958 b 18 6 STI No. 5 - 40 UNC b 4.000 3.589 18 6 3.312 STI M 5 × 0.8 6.039 5.519 5.173 G4 51 38 b 18 6 STI No. 6 - 32 UNC 4.536 4.021 3.678 b 18 6 GH3 38.1 25.4 STI M 6 ×1 7.299 6.649 6.216 G4 51 38 STI No. 6 - 40 UNF b 4.330 3.919 18 6 3.642 b 18 6 b 18 6 STI M 8 × 1.25 9.624 8.812 8.271 STI No. 8 - 32 UNC 5.197 4.681 4.338 G4 51 38 GH3 38.1 25.4 b 22 7 STI No. 8 - 36 UNF b 5.083 4.625 18 6 4.318 STI M 10 × 1.5 11.948 10.974 10.324 G5 64 51 b 18 6 STI No. 10 - 24 UNC 6.201 5.513 5.055 STI M 10 × 1.25 b 11.624 10.812 18 6 10.271 GH2 25.4 12.7 STI M 10 × 1 b 11.299 10.649 18 6 10.216 b 18 6 STI No. 10 - 32 UNF 5.857 5.341 4.998 b 22 7 GH2 25.4 12.7 STI M 12 × 1.75 14.273 13.136 12.379 G6 76 64 STI No. 12 - 24 UNC b 6.861 6.173 18 6 5.716 STI M 12 × 1.5 b 13.948 12.974 21 7 12.324 b 22 7 STI 1/4 - 20 UNC 8.000 7.174 6.626 STI M 12 × 1.25 b 13.624 12.812 21 7 12.271 GH3 38.1 25.4 STI M 14 × 2 b 16.598 15.299 22 7 14.433 b 18 6 STI 1/4 - 28 UNF 7.528 6.939 6.545 STI M 14 × 1.5 b 15.948 14.974 21 7 14.324 GH2 25.4 12.7 STI M 16 × 2 b 18.598 17.299 22 7 16.433 b 22 7 STI 5/16 - 18 UNC 9.771 8.854 8.244 STI M 16 × 1.5 b 17.948 16.974 21 7 16.324 GH3 38.1 25.4 STI M 18 × 2.5 b 21.248 19.624 30 10 18.542 STI 5/16 - 24 UNF b 9.313 8.624 18 6 8.167 STI M 18 × 1.5 b 19.948 18.974 24 8 18.324 b 22 7 STI 3/8 - 16 UNC 11.587 10.556 9.867 STI M 20 × 2.5 b 23.248 21.624 30 10 20.542 GH3 38.1 25.4 STI M 20 × 1.5 b 21.948 20.974 24 8 20.324 STI 3/8 - 24 UNF b 10.900 10.212 18 6 9.754 STI M 22 × 2.5 b 25.248 23.624 30 10 22.542 b 30 10 STI 7/16 - 14 UNC 13.469 12.291 11.506 STI M 22 × 1.5 b 23.948 22.974 24 8 22.324 GH3 38.1 25.4 STI M 24 × 3 b 27.897 25.948 30 10 24.649 b 18 6 STI 7/16 - 20 UNF 12.762 11.937 11.388 STI M 24 × 1.5 b 25.948 24.974 24 8 24.324 GH3 38.1 25.4 b 30 10 STI 1/2 - 13 UNC 15.238 13.968 13.122 GH3 38.1 25.4 STI 1/2 - 20 UNF b 14.350 13.524 18 6 12.976 STI 5/8 - 11 UNC b 18.875 17.376 30 10 16.376 STI 5/8 - 18 UNF b 17.708 16.791 21 7 16.181 STI 3/4 - 16 UNF b 21.112 20.081 21 7 19.392 Technical Information Technical-33 804