Shelf Pin Jig

I like drilling shelf pin holes in the top, bottom, and sides of a box so that it can be used vertically or horizontally. But that means the holes must be perfectly aligned if I want the shelves to be level regardless of how I set up the box. To get this kind of uniform spacing, I like to use a simple layout jig to mark my hole locations before I drill.

I made my jig out of ¾"-thick scrap material. The L-shape design lets me slide the jig flush along the edge of the board while I mark holes with a nail. Plus, the indentation left by the nail makes a nice starter hole for my drill bit. 

Start by marking the position of the first set of holes. Then simply slide the jig down the board and mark the next pair of holes. If you start your jig at the same place on every board, all shelf pin holes will be perfectly aligned.