It has the same features as our iGaging Micro-Adjust Wheel Gauge, but with 2 hardened steel cutting wheels that enable the scribing of parallel layout marks for mortise and tenon joints. Since the wheels slice, rather than tear the wood fibers, the tool is equally accurate when marking with or against the grain.
For mortises, you install the two 5/8” diameter wheel cutters with their bevels facing in toward each other (the bevel on the waste side). Using either the 1mm or 1/32nd inch graduated increments on the shaft, place the cutting wheels in the exact location desired (min of 3/8” apart) and lock them in place with the supplied set screws. If you are going to use a chisel to cut the mortises, then the chisel can be used as a reference in setting the width or distance apart of the wheel cutters.
An included stop collar is placed against the brass body face to ensure that the marking wheels don’t tilt or lift in use, especially when making marks that are extended further from the face. For tenons, reverse the wheel cutters so that their bevels are facing out from each other (bevel always on waste side).