Overall Thread Thread+Neck Shank Shank Size of Length of length length length length dia. square square L ℓ ℓn ℓs Ds K ℓk PO OX STI Spiral Pointed Taps for Helical Coil Wire Screw Thread Inserts, Oxided Size Class Code Chamfer L ℓ ℓn ℓs Ds K ℓk No. of Type (for blind hole) Spiral Fluted Taps (inch) (inch) (inch) (inch) (inch) (inch) (inch) flutes GH3 PUU07Q3NEX STI 7/16-14UNC 5P 4.331 1.024 - 2.205 0.429 0.322 0.5 3 3 GH4 PUU07Q4NEX GH3 PUU07N3NEX STI 7/16-20UNF 5P 4.331 1.024 - 2.205 0.429 0.322 0.5 3 3 (for through hole) Spiral Fluted Taps GH4 PUU07N4NEX GH3 PUU08R3NEX STI 1/2-13UNC 5P 4.331 1.024 - 2.205 0.480 0.36 0.562 3 3 GH4 PUU08R4NEX GH3 PUU08N3NEX STI 1/2-20UNF 5P 4.331 1.024 - 2.205 0.480 0.36 0.562 3 3 GH4 PUU08N4NEX (for through hole) Spiral Pointed Taps Hand Taps Carbide Taps Cemented Roll Taps Simple Inspection Tools Pipe Taps Thread Mills Dies Center Drills Centering Tools ANSI PO-18 245