14. Tap, Thread Limits Production data ■ for 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) + + + + P2 40 20 P3 60 40 G5 64 51 5/16 - 18 UNC 2B 7.938 7.021 49 23 6.411 No. 6 - 32 UNC 3.505 2.990 2.647 2B 38 18 GH1 12.7 0 GH1 12.7 0 P2 40 20 P2 40 25 5/16 - 24 UNF 2B 7.938 7.249 46 20 6.792 G5 64 51 GH1 12.7 0 No. 6 - 40 UNF 3.505 3.094 2.817 2B 36 16 P2 40 20 5/16 - 32 UNEF 7.938 7.422 7.079 GH1 12.7 0 2B 44 18 P2 40 20 P3 60 40 G6 76 64 3/8 - 16 UNC 2B 9.525 8.494 53 25 7.805 No. 8 - 32 UNC 4.166 3.650 3.307 2B 39 18 GH1 12.7 0 GH1 12.7 0 P3 60 40 P2 40 20 3/8 - 24 UNF 2B 9.525 8.837 48 20 8.379 G5 64 51 GH2 25.4 12.7 No. 8 - 36 UNF 4.166 3.708 3.401 2B 38 17 P2 40 20 3/8 - 32 UNEF 9.525 9.009 8.666 GH1 12.7 0 2B 46 18 P2 40 20 P3 60 40 G6 76 64 7/16 - 14 UNC 2B 11.112 9.934 56 27 9.149 No. 10 - 24 UNC 4.826 4.138 3.680 2B 42 20 GH1 12.7 0 GH1 12.7 0 P3 60 40 P2 40 20 7/16 - 20 UNF 2B 11.112 10.287 51 22 9.738 G5 64 51 GH1 12.7 0 No. 10 - 32 UNF 4.826 4.310 3.967 2B 40 18 7/16 - 28 UNEF P2 11.112 10.523 40 20 10.130 GH1 12.7 0 P3 60 40 P2 40 20 1/2 - 13 UNC 2B 12.700 11.430 58 28 10.584 No. 12 - 24 UNC 2B 5.486 4.798 43 20 4.341 GH1 12.7 0 GH1 12.7 0 P3 60 40 P2 40 20 1/2 - 20 UNF 2B 12.700 11.874 52 23 11.326 No. 12 - 28 UNF 2B 5.486 4.897 42 19 4.503 GH1 12.7 0 GH1 12.7 0 1/2 - 28 UNEF P2 12.700 12.111 40 20 11.717 No. 12 - 32 UNEF P2 5.486 4.971 40 20 4.627 P3 60 40 P2 40 20 9/16 - 12 UNC 2B 14.288 12.913 60 29 11.996 G7 89 76 GH3 38.1 25.4 1/4 - 20 UNC 6.350 5.524 4.976 2B 46 22 P3 60 40 GH1 12.7 0 9/16 - 18 UNF 2B 14.288 13.371 54 23 12.761 P2 40 20 GH2 25.4 12.7 G6 76 64 9/16 - 24 UNEF P2 14.288 13.599 40 20 13.142 Technical Information 1/4 - 28 UNF 6.350 5.761 5.367 2B 43 19 GH1 12.7 0 P2 40 20 1/4 - 32 UNEF 6.350 5.834 5.491 2B 42 18 Technical-29 800