A scriber is a hand tool used in metal work to mark lines on workpieces, prior to machining.

The workpiece is held against an angle plate so that it is perpendicular to the surface plate; the scriber block is then adjusted to the required height and used to scribe a line parallel with the table, by sliding the block along the table's surface.

The upright post can be adjusted to tilt back or forward, effectively moving the scriber point up or down in a controlled fashion; coarse adjustments are made by sliding the scriber along its clamping block.

The scriber block may also be used in place of a dial indicator to detect run out (a variation in concentricity) of a workpiece mounted in a four-jaw chuck.

The scriber point acts as a visual reference against which any variation in the workpiece can be judged.