Mortise gauge plan - Wedge version

Mortise gauges are made with two spurs (nails) which mark two lines parallel to the edge of a workpiece, showing the position of a tenon or mortise or a similar joint. This avoids having to score two lines separately, and makes for greater accuracy. The spurs must be able to move independently, and be locked in any position by the  fence. The spurs are made from nails cut down and hammered into the ends of each half of the stem.