National pipe thread - wikipedia National pipe thread Threaded pipe and elbow. The pipe has a male NPT thread, while the elbow is female. American National Standard Pipe Thread standards, often called national pipe thread standards for short, are U.S. national technical standards for screw threads used on threaded pipes and pipe fittings. They include both tapered and straight thread series for various purposes including rigidity, pressure - tight sealing, or both. The various types are each named with a symbol and a full name ; examples of the symbols include NPT, NPS, NPTF, NPSC, and others. MIP is an acronym for male iron pipe, and FIP is an acronym for female iron pipe. Outside the United States, some US pipe threads are found, as well as many British Standard Pipe threads and ISO 7 - 1, 7 - 2, 228 - 1, and 228 - 2 threads. Contents 1 Types 2 Use 3 Specifications 3.1 Thread form 3.2 National pipe taper fuel ( NPTF ) 4 Standard sizes 5 History 6 See also 7 References 8 Bibliography 9 External links Types The various types are each named with a symbol and a full name, as follows : Symbol Shorthand expansion Full name NPT national pipe taper American National Standard Taper Pipe Thread Tapered for sealing, often without any thread sealant ; for connections in nearly every type of service NPS national pipe straight American National Standard Straight Pipe Thread For rigidity ; sealable only with sealant ; sometimes male straight enclosed by female tapered for low - pressure sealing NPSC national pipe straight -- coupling American National Standard Straight Pipe Thread for Couplings For general couplings NPSF national pipe straight -- fuel Dryseal USA ( American ) Standard Fuel Internal Straight Pipe Thread Internal only, straight NPSH national pipe straight -- hose American National Standard Straight Pipe Thread for Hose Couplings For hose couplings NPSI national pipe straight -- intermediate Dryseal USA ( American ) Standard Intermediate Internal Straight Pipe Thread Similar to NPSF but slightly larger ; internal only, straight NPSL national pipe straight -- locknut American National Standard Straight Pipe Thread for Loose - fitting Mechanical Joints with Locknuts For use with locknuts NPSM national pipe straight -- mechanical American National Standard Straight Pipe Thread for Free - fitting Mechanical Joints For various rigid mechanical uses NPTF national pipe taper -- fuel Dryseal USA ( American ) Standard Taper Pipe Thread For dryseal connections in nearly every type of service, especially fuel connections NPTR national pipe taper -- railing American National Standard Taper Pipe Thread for Railing Joints For railings PTF - SAE SHORT pipe taper, fuel, SAE, short Dryseal SAE Short Taper Pipe Thread Named after SAE International ; similar to NPTF but one turn shorter Use Threaded pipes can provide an effective seal for pipes transporting liquids, gases, steam, and hydraulic fluid. These threads are now used in materials other than steel and brass, including PTFE, PVC, nylon, bronze, and cast iron. The taper on NPT threads allows them to form a seal when torqued as the flanks of the threads compress against each other, as opposed to parallel / straight thread fittings or compression fittings in which the threads merely hold the pieces together and do not provide the seal. The various types of pipe threads are designed for use both with or without thread sealants, as particular applications demand. The sealants, where used, are typically thread seal tape or pipe dope ( sometimes plumber 's putty ). As the thread body is tapered ( 0.75 in / ft or 62.5 mm / m ), a larger diameter keeps compressing into a smaller diameter and finally forms a seal ( no clearance remains between the crests and roots of the threads because of the taper ). This means that NPT fittings should be burr - free and lubricated using a lubricant like lubricating paste or thread seal tape. The use of tape also helps to limit corrosion on the threads, which otherwise can make future disassembly nearly impossible. Commonly used sizes are ​ ⁄, ​ ⁄, ​ ⁄, ​ ⁄, ​ ⁄, 1, ​ 1 ⁄, ​ 1 ⁄, and 2 inch, appearing on pipes and fittings by most U.S. suppliers. Sizes smaller than ​ ⁄ inch are occasionally used for compressed air, while sizes larger than 2 inches are uncommon, due to the use of alternative methods of joining that are used with these larger sizes. Specifications NPT is defined by ANSI / ASME standard B1. 20.1. The taper rate for all NPT threads is 1 inch of diameter in 16 inches of length ( ⁄ inch per foot or 62.5 millimeters per meter ) measured by the change of diameter ( of the pipe thread ) over distance of thread. The angle between the taper and the center axis of the pipe is tan ( ​ ⁄ ) = 1.7899 ° = 1 ° 47 ′ 24 ''. The standard for Nominal Pipe Size ( often abbreviated NPS, which should not be confused with the symbol NPS for the straight thread form standard ) is loosely related to the inside diameter of Schedule 40 series of sizes. Because of the pipe wall thickness of Schedule pipe, the actual diameter of the NPT threads is larger than the Nominal Pipe Size outside diameter, and considerably so for small sizes. Pipe of a given size in a different Schedule than Schedule 40 provides a different wall thickness, while maintaining the same outside diameter and thread profile as Schedule 40. Thus the inside diameter of a given size of Schedule pipe differs from the Nominal Pipe Size, while outside diameters for a given nominal Schedule size are the same between Schedules. Thread form NPT and NPS threads have a 60 ° included angle and have a Sellers thread form ( flattened peaks and valleys ). National pipe taper Fuel ( NPTF ) National Pipe Taper Fuel ( NPTF ), also called Dryseal American National Standard Taper Pipe Thread, defined by ASME B1. 20.3, is designed to provide a more leak - free seal without the use of PTFE tape ( often referred to by the popular brand name `` Teflon '' ) or other sealant compound. NPTF threads have the same basic shape but with crest and root heights adjusted for an interference fit, eliminating the spiral leakage path. Standard sizes American Society of Mechanical Engineers National Pipe Thread Taper ( NPT ) Nominal pipe size Thread density Thread pitch Hand - tight engagement Effective thread Overall length Actual outside diameter, OD Tap drill Length Turns Diameter Length Turns Diameter inch inch ) inch mm inch inch inch inch inch inch mm inch mm ​ ⁄ 27 0.03703704 0.9407 0.1600 4.32 0.28118 0.2611 7.05 0.2875 0.3896 0.313 7.950 ​ ⁄ 27 0.03703704 0.9407 0.1615 4.36 0.37360 0.2639 7.13 0.38000 0.3924 0.405 10.287 0.339 8.6106 ​ ⁄ 18 0.05555555 1.4111 0.2278 4.10 0.49163 0.4018 7.23 0.50250 0.5946 0.540 13.716 ⁄ 11.113 ​ ⁄ 18 0.05555555 1.4111 0.2400 4.32 0.62701 0.4078 7.34 0.63750 0.6006 0.675 17.145 ⁄ 14.684 ​ ⁄ 14 0.07142857 1.8143 0.3200 4.48 0.77843 0.5337 7.47 0.79178 0.7815 0.840 21.3360 ⁄ 18.2563 ​ ⁄ 14 0.07142857 1.8143 0.3390 4.75 0.98887 0.5457 7.64 1.00178 0.7935 1.050 26.6700 ⁄ 23.4156 ​ 11 ⁄ 0.08695652 2.2087 0.4000 4.60 1.23863 0.6828 7.85 1.25631 0.9845 1.315 33.4010 1 ⁄ 29.3688 ​ 1 ⁄ ​ 11 ⁄ 0.08695652 2.2087 0.4200 4.83 1.58338 0.7068 8.13 1.60131 1.0085 1.660 42.1640 1 ⁄ 38.1000 ​ 1 ⁄ ​ 11 ⁄ 0.08695652 2.2087 0.4200 4.83 1.82234 0.7235 8.32 1.84131 1.0252 1.900 48.2600 1 ⁄ 44.0531 ​ 11 ⁄ 0.08695652 2.2087 0.4360 5.01 2.29627 0.7565 8.70 2.31630 1.0582 2.375 60.3250 2 ⁄ 56.3563 ​ 2 ⁄ 8 0.12500000 3.1750 0.6820 5.46 2.76216 1.1375 9.10 2.79063 1.5712 2.875 73.0250 2 ⁄ 66.6750 8 0.12500000 3.1750 0.7660 6.13 3.38850 1.2000 9.60 3.41563 1.6337 3.500 88.9000 3 ⁄ 82.5500 ​ 3 ⁄ 8 0.12500000 3.1750 0.8210 6.57 3.88881 1.2500 10.00 3.91563 1.6837 4.000 101.6000 3 ⁄ 95.2500 8 0.12500000 3.1750 0.8440 6.75 4.38713 1.3000 10.40 4.41563 1.7337 4.500 114.3000 4 ⁄ 107.9500 ​ 4 ⁄ 8 0.12500000 3.1750 5.000 127.0000 4 ⁄ 120.6500 5 8 0.12500000 3.1750 0.9370 7.50 5.44929 1.4063 11.25 5.47863 1.8400 5.563 141.3002 5 ⁄ 134.1438 6 8 0.12500000 3.1750 0.9580 7.66 6.50597 1.5125 12.10 6.54063 1.9462 6.625 168.2750 6 ⁄ 161.1313 8 8 0.12500000 3.1750 1.0630 8.50 8.50003 1.7125 13.70 8.54063 2.1462 8.625 219.0750 10 8 0.12500000 3.1750 1.2100 9.68 10.62094 1.9250 15.40 10.66563 2.3587 10.750 273.0500 12 8 0.12500000 3.1750 1.3600 10.88 12.61781 2.1250 17.00 12.66563 2.5587 12.750 323.8500 14 8 0.12500000 3.1750 1.5620 12.50 13.87263 2.2500 18.00 13.91563 2.6837 14.000 355.6000 16 8 0.12500000 3.1750 1.8120 14.50 15.87575 2.4500 19.60 15.91563 2.8837 16.000 406.4000 18 8 0.12500000 3.1750 2.0000 16.00 17.87500 2.6500 21.20 17.91563 3.0837 18.000 457.2000 20 8 0.12500000 3.1750 2.1250 17.00 19.87031 2.8500 22.80 19.91563 3.2837 20.000 508.0000 24 8 0.12500000 3.1750 2.3750 19.00 23.86094 3.2500 26.00 23.91563 3.6837 24.000 609.6000 Hand - tight and effective thread engagement lengths History In 1864, William Sellers, the president of Franklin Institute, presented a standard for nuts, bolts, and screws. Out of this effort came the first United States Standard threads, including pipe threads. ( See also Screw thread § History of standardization. ) See also AN thread British standard pipe thread Fire hose thread Garden hose thread Panzergewinde Thread angle Threaded pipe Gender of connectors and fasteners References ^ Jump up to : Machinery 's Handbook ( 1996 ), pp. 1772 -- 1781. Jump up ^ Cauldwell, Rex ( 2006 ). Plumbing. Newtown, CT : Taunton Press. ISBN 1561588172. ^ Jump up to : Machinery 's Handbook ( 1996 ), pp. 1776 -- 1778. Jump up ^ http://www.micromold.com/threaded_piping.html PTFE threaded pipe and fittings manufacturer Jump up ^ http://www.hemcogages.com/ansi.htm Jump up ^ Engineering toolbox ^ Jump up to : http://www.piping-designer.com/index.php/disciplines/mechanical/84-stationary-equipment/fastener/1156-national-pipe-thread?title=National_Pipe_Thread Jump up ^ https://www.engineerily.com/1304161-bsp-and-npt-threads-detailed-explanation-differences.htm Bibliography Oberg, Erik ; Jones, Franklin D. ; Horton, Holbrook L. ; Ryffel, Henry H. ( 1996 ), Green, Robert E. ; McCauley, Christopher J., eds., Machinery 's Handbook ( 25th ed. ), New York, NY, USA : Industrial Press, ISBN 978 - 0 - 8311 - 2575 - 2, OCLC 473691581. External links NPT Pipe Thread Dimensions ASME B1. 20. - 1983 Pipe Threads, General Purpose, Inch ( 1 ) pipeandhose.com ( 2 ) Retrieved from `` https://en.wikipedia.org/w/index.php?title=National_pipe_thread&oldid=841310403 '' Categories : Thread standards Piping Plumbing Standards of the United States Hidden categories : Pages using div col without cols and colwidth parameters Talk Contents About Wikipedia Deutsch Español Français Русский Svenska 中文 Edit links This page was last edited on 15 May 2018, at 02 : 06. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: basic dimensions for npt american national taper pipe threads
Answer: 1 inch of diameter in 16 inches of length