Thispage provided the thread dimensions of 1/8 - 27 NPTF. NPTF stands for National Pipe Thread Fuel, based on ASTM B1.20.3. It is also called Dryseal Pipe Thread. It is a variation of the more popular NPT thread standard based on ASTM B1.20.1. Learn more about NPTF and the difference between NPTF and NPT. Allpipe taps furnished with a 2-1/2 to 3-1/2 thread chamfer. Npt threads require the use of a sealer like Teflon tape or pipe compound. Uncoated tools feature just the base substrate without any additional treatment or coatings and are suitable for a wide range of applications. (NPT) Pipe Tap and the matching size Drill America Black FromStandard Sets. Once you know your wire diameter, you need to find out what is the premissable Measurement for your pitch diameter (Depending on the class). Use our Over Wire Calculator to find out! 3-8 NPT : Basic Thread Dimensions (Pitch, minor & major diameters, depth, lead), Tolerance range for all applicable classes and much more. ThreadmillingNPT Threads. Over a year ago, we created a super helpful threadmilling calculator because we wanted to get reliable results on the first try. Seemsto be a rash of NPT going today. Other guy was working on 1/2x 14 NPT. I've run a lot of 3/4x14 NPT. We drill it .875", which of course is going to come out a bit bigger. Start point is X.9,Z.1, and final X is .995, with a Z-.800. R line in the Fanuc 21iT is the taper, and its at .0887. Feed is .07143. This is in the Fanuc two line G76 1 black or galvanized pipe has an o.d. of 1.315", the i.d will depend on what schedule it is. Sch. 40 is 1.049" and Sch. 80 is .957". Normally, if you subtract the pitch (1/tpi) from the major diameter, you would get the tap drill diameter for a 75% thread but since pipe threads are tapered and must seal to the fittings, requiring a 100% thread, qHxx3c. Findthe drilled hole size for a 65% thread on a 4 mm x 1.00 (M4) tapped hole: Look for the 1.00 mm pitch in the chart's first column. Match this row to the 65% thread percentage column. The result is 0.8444. The result is 4.0 mm - 0.8444 mm = 3.1666 mm, which is the necessary diameter for the drilled hole. Carbonsteel pipe taps are designed to clean and or re-thread damaged or jam pipe threads ; Also called 'pipe taps', National Pipe Taper (NPT) taps are appropriate for threading a wide variety of materials both ferrous and non-ferrous. Alarger Thread height means a smaller tap drill size. A smaller Thread height means a larger tap drill size. Why Is it important? Since the feed always equals the thread pitch and the entire thread depth is machined in one pass by definition, these factors are not in our control. The thread depth is a primary factor (Next to the cutting speed) influencing a ThreadSize NPTF O.D. Male Thread Large Dia. D Min. Thread Length B Min. Tap Drill Depth 1) E Chmf. Dia. 1/8-27 0.41 0.31 0.38 0.42 1/4-18 0.55 0.44 0.47 0.55 3/8-18 0.68 0.47 0.53 0.69 1/2-14 0.85 0.59 0.69 0.85 3/4-14 1.06 0.63 0.75 1.06 1-11 1/2 1.33 0.75 0.84 1.34 1 1/4-11 1/2 1.67 0.78 0.84 1.68 1 1/2-11 1/2 1.91 0.81 0.88 1.92 2-11 1/2 2. NPT : Pipe and Fitting Thread Dimensions and Tolerances. All the relevant data for this tread in one spot. 1 1/2-11.5 NPT : Pipe and Fitting Thread Dimensions and Tolerances. Tap Drill Size (T) 1.7344: 44.054: 1 1/2-11.5 NPT - Internal (Fitting) Drawing. Overview Drawing. Profile Drawing. 1 1/2-11.5 NPT - Tolerances. Property Minimum 38 NPT - drill with a 37/64 bit to a minimum depth of 0.8125 & tap to a depth of 0.7565; 1/2 NPT - drill with a 45/64 bit to a minimum depth of 1.03125 & tap to a depth of 0.96025; Following these recommendations will only give you a full thread for the first 2 to 3 threads. External Links. Drill & Tap Chart

1 2 npt thread drill size