re: Metric vs imperial

I broke down and bought the metric and imperial Thread Detective® Thread Gauges through Rockler and Amazon.

https://www.amazon.com/Bolt-Thread-Checker-Inch-Metric/dp/B003FJW0GK/ref=pd_lpo_vtph_60_bs_tr_t_2/145-4692603-4646461?_encoding=UTF8&psc=1&refRID=V8G3WRTC5DBVF49S1BBD