M14× 1.5 mm. M14 × 2 mm. M16 × 1.5 mm. External, Internal. Aluminum. 00000000. 000000. Choose from our selection of thread charts in a wide range of styles and sizes. In stock and ready to ship. NationalStandard Taper Pipe Threads Size NPT Chart; Internal British ISO Pipe Threads (Whitworth Form) Table per. BS EN ISO 228; Standard Taper Pipe Threads NPT Basic WhatSize Drill Bit for 3/8” NPT Tap? You need a 37/64” drill bit for a 3/8″ NPT Tap. Here are some other common closely related sizes and the drill bits they require in case you 78 26 20.8 1 26 24.3 *Taper pipe threads of NPT-NPTF* NATIONAL PIPE TAPER 1:16 (60º) Tap Size TPI Drill Only* Drill & Reamer 1-1/2 11-1/2 44 43.5 2 11-1/2 55.5 55.0 NPSF NATIONAL PIPE STRAIGHT (60º) Tap Size TPI Tapping Drill mm 1/8 27 8.6 1/4 18 11.3 3/8 18 14.5 1/2 14 18.0 THREAD FORMING (FLUTELESS TAPS) Thereare 6 types of class fit for unified threads: Classes 1A and 1B - Loosest tolerance, it’s very rare. Usually used when quick assembly/disassembly is required. Classes 2A and 2B - “Medium” tolerance, it’s the most common fit. This is the best option to balance thread performance and convenience. Choosefrom our selection of 3/8"-24 taps, including over 70 products in a wide range of styles and sizes. In stock and ready to ship. Cut and repair threads and drill holes in many different sizes. Assortments include various sizes of helical inserts and a tap, a drill bit, and an installation tool for each thread size. Forexample, if you have a 1/8” NPT pipe tap, the R type is the appropriate drill bit to use with this tap. If the pipe tap is tapered, the ideal drill size is 21/64mm in fraction form or 0.339”. For non-tapered or straight pipe taps, use a drill size of 11/32mm or 0.344”. This delivers 27 threads per inch. 48 NPT : Pipe and Fitting Thread Dimensions and Tolerances. All the relevant data for this tread in one spot. 4-8 NPT : Pipe and Fitting Thread Dimensions and Tolerances. (E 3) 4.31875: 109.696: Tap Drill Size (T) N/A: N/A: 4-8 NPT - Internal (Fitting) Drawing. Overview Drawing. Profile Drawing. 4-8 NPT - Tolerances. Property Minimum Maximum; stooGbn.