There are so many things today which utilize threads. If you look around your house or at your car, you may find literally thousands of items held together or constructed with threads. Many kinds of threads are not created in molds. In fact they need to be literally ground or cut into the materials. Here is a closer look at the thread grinding and cutting processes to give you a better idea of what goes on.
Thread Production
Creating threads is the most used method of machining done today. Perhaps the quickest and easiest way to thread something is to cut threads into objects like metal pipe. The most basic type of thread cutting is done manually with taps and dies. This is only for small jobs and is not usually done in industry today. It is simply too labor intensive and costly.
Single Point Cutting
With this process, a thread is cut into material from a single point and as the part moves, the thread is created. In order to create either internal or external threads, the part may be sent through the machine several times to get the desired depth.
Milling is not thread grinding but is a process using a milling cutter. Unlike single point thread cutting, this method is much faster and can be computerized (CNC) for use in mass production. The same equipment can be used to create both left handed and right handed threads.
Thrilling
Thrilling is a combination of both threading and drilling. It uses a special CNC machine for milling. The tool uses the point for cutting and the shaft of the tool has threads which utilize a special countersinking cutter. First the cutter drills into the part and then the threads are created in a circular manner. Drilling, chamfering and threading are accomplished in one operation.
Thread Grinding
Grinding threads is done with special grinding wheels which perfectly match the threads to be created. Thread grinding makes it possible to create highly accurate threads for applications requiring high tolerance threading. In addition, grinding can be used on very hard metals which are not easy to thread with other methods.
Axial feed center thread grinding is used to create precision threads and a single point cutter (grinding tool) creates threads as the part turns on a lathe. This is the most accurate method for grinding threads. Other methods of thread grinding are sometimes used to create parts like headless threaded screws and bolts.
