Thereare four types of NPT threads: National Pipe Taper (NPT) National Pipe Straight (NPS) National Pipe Taper For Fuel (NPTF) NPT Threads Dimensions. NPT Designationof Dryseal Pipe Threads: The standard Dryseal pipe threads are designated by specifying in sequence nominal size, thread series symbol, and class: Examples:1⁄8-27 NPTF-1; 1⁄8-27 PTF-SAE SHORT; and 3⁄8-18 NPTF-1 AFTER PLATING. Table 8. Suggested Tap Drill Sizes for Internal Dryseal Pipe Threads uZfTED. 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. Therecommended drill size for a 3/8 inch pipe tap is 29/64th of an inch for both metal and wood applications. It is important to use a drill bit that is slightly larger than the desired thread size to ensure accuracy. With the right drill size and the correct technique, you can create perfect threads in pipes with ease. Choosefrom our selection of pipe thread repair inserts in a wide range of styles and sizes. In stock and ready to ship. BROWSE CATALOG. Abrading & Polishing; Building & Grounds; 3/8 " 3/8 " 12: Drill Bit, Through-Hole Tap, Installation Tool: Bendingcalculator National Pipe Threads Tap Drill Chart NPT and NPS threads share similarities in thread angle, shape and pitch (TPI – threads per inch). However, they PipeThread Drilled Hole Sizes Drill sizes given are the ‘closest’ drill size. NOMINAL SIZE NPT NPTF NPSC NPSM NPSF NPSI BSPT BSPP 1/16 - 27 D (0.246) D 1/4 - 19 0.4375 0.4531 3/8 - 18 0.5625 0.5781 0.5781 0.6093 0.5781 0.5781 3/8 - 19 0.5781 0.5937 1/2 - 14 0.7031 0.7031 0.7187 0.75 0.7187 0.7187 0.7187 0.7343 5/8 - 14 0.8125 TAPDRILL SIZES Machine Screws IPS Pipe Recommended NPT, NPTF Screw Tap Drill Size Nominal w/o Reamer Size Drill Decimal Size Drill Decimal 2-56 50 0.0700 1/16-27 C 0.2420 3-48 47 0.0785 1/8-27 Q 0.3320 3-56 46 0.0810 1/4-18 7/16 0.4375 4-40 43 0.0890 3/8-18 9/16 0.5625

3 8 npt thread drill size