Thread Ring Gage 00-90 .050" (Over sized Non Standard) UNS-2A; Set "Go" and "No-Go" members, Precision Thread Gage made of High Speed Steel then hardened. Picture is representative of part previously stocked we have two sets made in Switzerland for our brand. This thread is used primarily for jewelry and eye wear fasteners. The thread major diameter is .050". We offer screws and hex nut in this thread size.