Get double duty from a combination square
Some tasks require using a combination square for measuring and for drawing perpendicular lines, and a marking gauge for drawing lines parallel to an edge on a long work surface. Wouldn't it be nice if one tool could do both jobs?
Drill a 1⁄16 " hole through the center of the guide slot in the blade at the 1" mark as shown. Insert a pencil tip or a scribe through the hole for marking. To figure the distance from the mark to the edge of the stock, remember to subtract 1" from the distance shown on the scale where it intersects the crosspiece. Hold the pencil and square steady as you mark.
—R.L. Watkins, Naches, Wash.