Dietert Slot Groove Depth Gauge Dial Indicator Gage

Offering this hard to find precision gauge, designed to inspect slots and grooves up to .100" deep.  The dial is in .001" graduations and is marked "HARRY W. DIETERT CO. DETROIT MICHIGAN PAT. NO. 2130269".  The patent number reflect a date of 1938.  The dial indicator has a total movement of .100", and there is a spring loaded swivel, (with a spring return) carbide blade tip on the end of the indication shaft.  The tip is in very good shape and is precision ground to a sharp tip end.  The swivel feature is precise, so you will get an accurate measurement even if you need to turn the tip to position the gage correctly.  The bottom of the aluminum gauge frame is hardened steel insert, is precision flat ground so the gage is designed to measure from a flat surface, with the hardened steel insert setting on a flat surface.  A very nicely made gauge, not damaged, dial indicator work very smoothly, has a good lens, with some minor yellowing, and some surface wear, but not cracked, the lens ring is also adjustable to set a specific depth if desired.  A very unique and hard to find, quality make precision tool!