When you are connecting different pieces of pipe, the threads that you are using can make a big difference. Standard bolt threading is designed to offer a secure fit, but if you want your pipes to have a leak free fil, nation pipe thread (NPT) standard is the optimum choice for creating a solid seal. Nowadays, thanks to the modern marvel that is CNC machining, you can find carbide thread mills for NPT threads that can create secure threads in seconds.
There are a lot of different styles of pipe threading that are going to be suitable for different applications. Threaded pipes are used to transport a wide range of liquids, gases, steam, and hydraulic fluid. Using the proper threads of your pipe’s connection will ensure a leak free seal when transporting any of these materials.
NPT threads are unique because they contain a tapered design to the threads. Straight threads are easy to manufacture and are commonly seen on bolts and some pipes, but these are far from the best option available. The tapered thread design of NPT, along with the truncated roots and crests of the threaded surface, help these pipes to fit together without the need for additional thread sealants. As the male and female portions of the pipes are attached, the tapered thread surface creates a much tighter pull than a straight thread, helping to produce a tight seal.
When they were originally conceived, NPT threads were not designed with high pressure systems in mind. Even though the threads are already designed to create a much more solid fit than a straight thread, adding some tape or another form of thread sealant is advised when using NPT threaded pipes for high pressure applications. Typically they are best suited for applications like water lines where pressure rarely exceeds 60 pounds per square inch.
Special considerations also have to be taken when reusing pipes threaded with NPT style threads. Overtightening these pipes can easily crack the female connection while under tightening your pipes can cause leaks. Because the tapered NPT threads compress against each other they can distort when over tighten several times. There is no precise tightening standard for these threads, but care should be taken especially when dealing with older threads.
Creating NPT threads on pipes was a task once achieved using specially designed tap and die tools. CNC machining is quickly replacing these classic tools as a method of fast and efficient thread production. The cutting tools, known as end mills, are guided by preprogrammed instructions that precisely guide the path of the tool during machining.
The fastest means of thread production are tools known as full form thread mills. Using carbide thread mills for NPT threads can complete the cutting of a threaded pipe in just one 360 degree pass. The tool itself has several cutting “teeth” along its surface and they are designed to offset the cut by the spacing between threads while cutting. This helps produce a helical thread instead of a series of circular cuts. You can also cut the entire surface of a thread one turn at a time. These single pitch tools are slower, but a single tool can produce a wide range of thread styles and pitches.
To find a wide range of solid carbide thread milling cutters, visit Online Carbide. They are an American manufacturer dedicated to producing high quality end mills and drill bits which are sold directly to the consumer. You can find full form carbide thread mills for NPT, NPTF, UN, and metric threads. If you have any questions about their tools feel free to contact their team by calling 630-238-1424 or sending an email to [email protected]