Hold-Down (Holdfast)

A holdfast (or hold-down) secures a workpiece flat against a workbench top, rather than gripping it from the side the way a vise does -- the shaft drops into a hole in the benchtop and a curved arm presses down on the work, typically locked in place by a sharp rap with a mallet that wedges the shaft against the hole's sides through friction. A more modern hold-down clamp works the same functional role using a cam or screw mechanism instead of friction.

It's especially suited to hand-tool work like planing or chiseling, where both hands need to be free to work the tool and a side-mounted vise either can't reach the spot or would get in the way -- a board being hand-planed near its center, well away from any bench edge, is exactly the case a face vise can't handle but a holdfast handles easily.