Why use class 3 threads?
Why use class 3 threads? Classes 2A and 2B are the most common thread classes in use, offering a balance of ease of manufacture, cost, and performance. Classes 3A and 3B are best suited where close tolerances, safety, and strength are required, and thus are frequently specified for socket cap and socket set screws.
Can you mix 2A and 3B threads?
The requirements for screw thread fits for specific application are predicated on end use and can be met by specifying the proper combinations of thread classes for the components. For example, a Class 2A external thread may be used with a Class 1B, 2B or 3B internal thread.