{"id":14451,"date":"2025-03-10T13:53:32","date_gmt":"2025-03-10T18:53:32","guid":{"rendered":"https:\/\/blog.misumiusa.com\/?page_id=14451"},"modified":"2025-04-16T12:40:29","modified_gmt":"2025-04-16T17:40:29","slug":"npt-thread-fitting-chart","status":"publish","type":"page","link":"https:\/\/blog.misumiusa.com\/npt-thread-fitting-chart\/","title":{"rendered":"NPT Thread Fitting Chart"},"content":{"rendered":"\n

Author: Scott Bredemann<\/a><\/p>\n\n\n\n

Updated<\/strong>: 03\/10\/2025 | Read Time<\/strong>: 4mins<\/p>\n\n\n\n

National Pipe Taper (NPT) threads are a widely used standard in North America for sealing pipe connections. Unlike straight threads, NPT<\/a> threads have a tapered profile, which ensures a tight and leak-resistant fit when properly assembled. The tapering allows the threads to form a mechanical seal by wedging together, often enhanced with thread sealants like PTFE tape or pipe dope.<\/p>\n\n\n\n

This NPT Thread Size Chart provides specifications for various nominal pipe sizes, including outside diameter, threads per inch (TPI), pitch, taper rate, thread length, effective thread length, and hand-tight engagement length. These dimensions help engineers, manufacturers, and technicians select the correct thread size for fluid and gas piping systems.<\/p>\n\n\n\n

Nominal Size<\/strong><\/td>Threads Per Inch<\/strong><\/td>Outside Diameter (in)<\/strong><\/td>Pitch (in)<\/strong><\/td>Taper (in\/ft)<\/strong><\/td>Thread Length (in)<\/strong><\/td>Effective Thread Length (in)<\/strong><\/td>Hand-Tight Engagement (in)<\/strong><\/td><\/tr>
1\/16<\/td>27<\/td>0.3125<\/td>0.03704<\/td>3\/4<\/td>0.2611<\/td>0.1615<\/td>0.0644<\/td><\/tr>
1\/8<\/td>27<\/td>0.405<\/td>0.03704<\/td>3\/4<\/td>0.2639<\/td>0.1822<\/td>0.0806<\/td><\/tr>
1\/4<\/td>18<\/td>0.54<\/td>0.05556<\/td>3\/4<\/td>0.4018<\/td>0.2639<\/td>0.1142<\/td><\/tr>
3\/8<\/td>18<\/td>0.675<\/td>0.05556<\/td>3\/4<\/td>0.4078<\/td>0.2756<\/td>0.1177<\/td><\/tr>
1\/2<\/td>14<\/td>0.84<\/td>0.07143<\/td>3\/4<\/td>0.5337<\/td>0.3209<\/td>0.1575<\/td><\/tr>
3\/4<\/td>14<\/td>1.05<\/td>0.07143<\/td>3\/4<\/td>0.5457<\/td>0.3396<\/td>0.1626<\/td><\/tr>
1<\/td>11.5<\/td>1.315<\/td>0.08696<\/td>3\/4<\/td>0.6828<\/td>0.402<\/td>0.2006<\/td><\/tr>
1 1\/4<\/td>11.5<\/td>1.66<\/td>0.08696<\/td>3\/4<\/td>0.7068<\/td>0.4252<\/td>0.2074<\/td><\/tr>
1 1\/2<\/td>11.5<\/td>1.9<\/td>0.08696<\/td>3\/4<\/td>0.7235<\/td>0.4418<\/td>0.2124<\/td><\/tr>
2<\/td>11.5<\/td>2.375<\/td>0.08696<\/td>3\/4<\/td>0.7565<\/td>0.4752<\/td>0.2219<\/td><\/tr>
2 1\/2<\/td>8<\/td>2.875<\/td>0.125<\/td>3\/4<\/td>1.1375<\/td>0.5793<\/td>0.25<\/td><\/tr>
3<\/td>8<\/td>3.5<\/td>0.125<\/td>3\/4<\/td>1.2<\/td>0.6083<\/td>0.2542<\/td><\/tr>
3 1\/2<\/td>8<\/td>4<\/td>0.125<\/td>3\/4<\/td>1.25<\/td>0.6313<\/td>0.2573<\/td><\/tr>
4<\/td>8<\/td>4.5<\/td>0.125<\/td>3\/4<\/td>1.3<\/td>0.6542<\/td>0.2604<\/td><\/tr>
5<\/td>8<\/td>5.563<\/td>0.125<\/td>3\/4<\/td>1.4063<\/td>0.7042<\/td>0.2667<\/td><\/tr>
6<\/td>8<\/td>6.625<\/td>0.125<\/td>3\/4<\/td>1.5125<\/td>0.7542<\/td>0.2729<\/td><\/tr>
8<\/td>8<\/td>8.625<\/td>0.125<\/td>3\/4<\/td>1.7125<\/td>0.8542<\/td>0.2854<\/td><\/tr>
10<\/td>8<\/td>10.75<\/td>0.125<\/td>3\/4<\/td>1.925<\/td>0.9542<\/td>0.2979<\/td><\/tr>
12<\/td>8<\/td>12.75<\/td>0.125<\/td>3\/4<\/td>2.125<\/td>1.0542<\/td>0.3104<\/td><\/tr>
14<\/td>8<\/td>14<\/td>0.125<\/td>3\/4<\/td>2.25<\/td>1.1042<\/td>0.3167<\/td><\/tr>
16<\/td>8<\/td>16<\/td>0.125<\/td>3\/4<\/td>2.45<\/td>1.2042<\/td>0.3292<\/td><\/tr>
18<\/td>8<\/td>18<\/td>0.125<\/td>3\/4<\/td>2.65<\/td>1.3042<\/td>0.3417<\/td><\/tr>
20<\/td>8<\/td>20<\/td>0.125<\/td>3\/4<\/td>2.85<\/td>1.4042<\/td>0.3542<\/td><\/tr>
24<\/td>8<\/td>24<\/td>0.125<\/td>3\/4<\/td>3.25<\/td>1.6042<\/td>0.3792<\/td><\/tr><\/tbody><\/table>
NPT Thread Fitting Chart<\/figcaption><\/figure>\n\n\n\n

MISUMI USA<\/a> carries a large array of products with NPT threads, including the following:<\/p>\n\n\n\n

Thread Pipe Fittings & Flanges – NPT (Male)<\/a><\/p>\n\n\n\n

Thread Pipe Fittings & Flanges – NPT (Female)<\/a><\/p>\n\n\n\n

Fittings for Steel & Copper Pipes-NPT
<\/a><\/p>\n\n\n\n

For questions on products related to NPT thread fittings, or any other product questions please connect<\/a> with our product experts and engineers. And, for more articles on things related to industrial manufacturing and engineering check out more of our blog<\/a>.<\/p>\n\n\n\n

Disclaimer
The content on this webpage is for informational purposes only. MISUMI makes no guarantees, expressed or implied, regarding the accuracy, completeness, or validity of the information. Performance parameters, tolerances, designs, materials, or processes should not be assumed to reflect third-party suppliers\u2019 or manufacturers\u2019 deliverables within MISUMI\u2019s network. Buyers are responsible for specifying their part requirements<\/p>\n","protected":false},"excerpt":{"rendered":"

Author: Scott Bredemann Updated: 03\/10\/2025 | Read Time: 4mins National Pipe Taper (NPT) threads are a widely used standard in North America for sealing pipe connections. Unlike straight threads, NPT threads have a tapered profile, which ensures a tight and leak-resistant fit when properly assembled. The tapering allows the threads to form a mechanical seal by wedging together, often enhanced with thread […]<\/p>\n","protected":false},"author":70,"featured_media":14463,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"om_disable_all_campaigns":false,"footnotes":""},"class_list":["post-14451","page","type-page","status-publish","has-post-thumbnail","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t