Harshman Gauges & Engineering Co. Offers Plain Gauges. Harshman Gauges & Engineering Co. Supplies Thread Ring, Plug Gauges, Thread Plug Gauges Thread Ring Gauges, etc. The Plain Gauges consist of Double End Limit Snap Gauges with Master Setting Ring, S/E & D/E Plug Gauges & Snap Gauges, Ring Set, Slip Gauges, Adjustable Snap Gauges, Dial Snap Gauges, etc. There is Keyway width Gauges, Measuring Pin Boxes, Morse taper [MT] Gauges, Sine Bars, Sine Centre, and Master Cylinders. Plain Carbide Gauges are supplied as per the specification of customers.