A dial caliper is one of the most important tools for measuring your works and monitoring the progress of machining cuts. It can measure outside and inside diameters as well as depth measurements. but did you know that with a twenty second modification, it can be made into the most versatile marking gauge in your shop?

The outside measuring jaws are pointed and converge to a point at their tips when fully closed. If you very carefully grind about 1/16" off the non moving jaw (the outside one) still maintaining the same angle so the moving jaw extends past the outside one, you can set the measurement directly on the dial and mark your work by passing the longer jaw along the edge of the work while the shorter one scribes the line. You must have a clean edge to measure from or else the accuracy of this procedure will be lost. To find the center line on a workpiece, you just measure across the width, divide in half, set the resulting number on the dial and scribe the line indexing from one of the edges you measured from. Complicated sets of locations can be quickly laid out on work by bluing the complete surface and scribing out all the lines working out of the same edges. Will can call these X and Y. After all the coordinate lines have been scribed, the hole locations will be at every point where the X and Y lines intersect. Now you can carefully center punch, drill, ream or thread as needed.