AmericanNational Standard Pipe Thread often called national pipe thread standards for short NPT, are U.S. national technical standards for screw threads used on threaded pipes and pipe fittings. Size & Pitch External Thread OD Internal Thread ID; inch : TPI : Max : Min : Max : Min: 1/8" 27 : 0.397 : 0.390 : 0.358 : 0.364 : 1/4" 18 : 0.526 34 0.7500 49/64 0.7656 25/32 0.7812 13/16 0.8125 53/64 0.8281 27/32 0.8438 7/8 0.8750 57/64 0.8906 29/32 0.9062 15/16 0.9375 61/64 0.9531 31/32 0.9688 1 1.0000 1-1/64 1.0156 1-1/32 1.0313 Screw Size Close Fit Free Fit No. or Diameter Diameter Equivalent Drill Size Decimal Equivalent Drill Size Decimal Equivalent Clearance Hole Drill Chart Whatsize is a 3/8 tap drill? For a 3/8-inch-16 tap, you would use a drill bit with a diameter of approximately 0.339 inches. UNF, and NPT threads. What size is a standard kitchen tap? A standard kitchen tap, referring to a faucet, typically has a threaded inlet of 1/2 inch or 3/8 inch, depending on the plumbing configuration. NominalSize BSPT Thread Form Type Major Diameter mm d=D Pitch mm p Threads per inch tpi Pitch Diameter mm d2=D2 Minor Diameter Male Thd. d3=D3 Thread Height H1 Rounding r Effective Thread Length mm External Tap Drill Diameter mm; R 1/16: 1/16" BSPT: 7.723: 0.907: 28: 7.142: 6.561: 0.581: 0.125: 2.5: BSW BSF BSPP BSPF BSPT 38 - 16 16-UN : Basic Thread Dimensions (Pitch, minor & major diameters, depth, lead), Tolerance range for all applicable classes and much more Dryseal Pipe Threads (NPTF) British Pipe Threads (BSP) ACME Trapezoidal Threads; Materials Menu Toggle. Tap Drill Sizes for 3/8 - 16 16-UN. If not specified, assume a thread depth of 75%. TappingNPT pipe threads. Thread starter Overland; Start date May 5, 2023; Replies 40 Views 2,484 1; 2; 3; If you drill the correct drill size thru, then maybe start with 10 complete turns of the tap handle to start. I've always left 8 threads on non-gaged stuff. Leaves a little room for a touch-up later if it's ever needed. 38" NPT Tap and Drill Set: 1/2" NPT Tap: 23/32" Drill Bit: 1/2" NPT Tap and Drill Set: 3/4" NPT Tap: 59/64" Drill Bit: 3/4" NPT Tap and Drill Set: 1" NPT Tap: 1-5/32" Drill Bit: 1" ProfileDrawing 3 - 8 NPTF - Tolerances * All other dimensions can be controlled only with gauges. 3 - 8 NPTF : NPT Fuel (Dryseal) Thread Dimensions and Tolerances. All the .

3 8 npt thread drill size