Conclusion ¾” NPT taps need a large drill bit size of 59/64 inches and can be used for a wide range of materials. They’re mostly used for cleaning and re-threading. If you’re gonna use them, make sure to have a sealer for the threads. The ¾” NPT tap is mainly used to cut pipes' internal threads. If you want to know what size drill FemaleNPTF Table U22 — NPTF Dimensions 1) For bottoming taps only. Table U23 — BSPT Dimensions 1) For bottoming taps only. Male BSPT Female BSPT Thread Size NPTF O.D. Thread Length B Min. Tap Drill Depth 1) E Chmf. Dia. 1/8-28 0.39 0.31 0.38 0.42 1/4-19 0.53 0.44 0.47 0.55 3/8-19 0.67 0.47 0.53 0.69 116-27 NPT : Pipe and Fitting Thread Dimensions and Tolerances. All the relevant data for this tread in one spot. 1/16-27 NPT : Pipe and Fitting Thread Dimensions and Tolerances. Tap Drill Size (T) 0.246: 6.248: 1/16-27 NPT - Internal (Fitting) Drawing. Overview Drawing. Profile Drawing. 1/16-27 NPT - Tolerances. Property Minimum Maximum; A1” NPT Tap needs a size drill bit of 1 5/32 inches or 1.1563 inches in decimals. NPT taps are also called pipe taps and don’t confuse them with NPTF taps and tapered taps like the 4-40 tap. NPT taps can be carbon 1- 1.0000 .9800 24.75mm .9700 31/32 This chart allows for drill oversize based on study done by the United States Cutting Tool Institute M A D E IN U S A W O R L D C A S 28 HANNIBAL CARBIDE TOOL, INC. • TEL 573-221-2775 • FAX 573-221-1140 • sales@hannibalcarbide.com ThePROPER tap drill for a 1/4″-20 thread is a #7, which is 0.201″ diameter. For a 1/4″-28 thread, use a #3 drill (0.213″ diameter). A 7/32″ drill is 0.219″ and will result in sloppy, weak threads on a 1/4″-20. A 13/64″ (0.203) drill would be a better choice if you only have fractional sizes available. 7/32″ is likely “close A1-¼” NPT Tap needs a drill bit size of 1 1/2 inches or 1.5 inches in decimals. NPT taps are also called pipe taps and don’t confuse them with NPTF taps and tapered taps like the 5/8-11 tap. The NPT refers to the pipe and fittings with tapered threads that follow National Pipe Thread specifications much like the 1/4″ NPT with a bit size HelicoilDrill Chart. The minimum drilling depths shown below allow for the following recommended practices: Countersinking the drilled hole to prevent a feather edge at the start of the tapped hole. 3/4 - 1-1/2 pitch of insert "set down" to allow for maximum production tolerance. Dimensions are shown for both plug and bottoming taps. For plug er8ssk.

1 4 npt thread drill size