Simple Thread Inspection Tool-SIT

We are tapping both Metric and Unified screws. The current method we use for the inspection of an internal screw thread is to insert a commercially available bolt into the tapped hole. This verifies the condition of the threads acceptability and we can check the thread at the processing site to judge the quality. Now we have received a request from our customer for large screws and they want us to inspect more carefully to control the tolerance of the thread to insure the high and low tolerance of the thread is being held. We know it is a good practice to inspect with the thread gauge “GP-6H” and “NP-6H” for tighter tolerances, but there are so many types of gauges making it a difficult situation in cost to measure all screw gauges. Is there a better way?