What is the difference between H2 and H3 on a tap?
What is the difference between H2 and H3 on a tap? In other words, an H1 limit is one . 0005 increment larger than the minimum limit or Go gage, an H2 is two . 0005 increments (or . 001) larger than the minimum limit, an H3 is three .
What does 2A and 2B mean for threads?
Classes 2A-2B Class 2A external threads have an allowance, Class 2B internal threads do not. Classes 2A and 2B, for most engineering applications, offer the optimum thread fit that balances fastener performance, manufacturing convenience and economy.
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.