Q: Can you explain to me what the difference is between cut and rolled threads?
A: Cut threads can also be referred to as machined threads. The machining cuts away the material to create the thread form. Rolled threads means the threads are formed by pressing the parts between 2 round dies or flat plates that already have the thread pitch machined onto their face. When the parts move, or roll, through the dies, the threads are formed by the applied pressure without cutting or removing any material. Rolled threads are more commonly requested as a rolled thread has a rounded root radius and the cold working of the thread rolling operation increases the strength of the material in the threads. For non heat treated bolts – rolled threaded parts have higher strengths than cut threads in the area where the thread was formed. However, for heat treated parts, rolled or cut threads have the same strength as the heat treatment dictates the strength.