Gauges are available in both 4H or 5H class of fits for metric threads, 2B or 3B for Unfied threads and close medium for Whitworth threads. The class of fit of finished assembly is dependent on the accuracy of the tapped hole. The result shows if the tapped hole for wire thread inserts gauges correctly. It is not possible to gauge the installed inserts because they are flexible. After the BaerCoil insert is installed, the Go Gauge occasionally does not enter freely. How ever the insert will always seat itself when the bolt is installed and tightened