Bradawl

Also called: awl, sprig bit

A bradawl is a small hand tool with a short, pointed blade set in a handle, pushed and twisted into wood to start a hole for a screw, nail or brad, a slender headless nail, before it is driven.

Marking and starting holes

A bradawl or a pilot drill can mark a screw-hole location through a hardware backplate, the metal plate fitted behind a handle or lock. A bradawl can also mark where a lock's key should sit, and where a spindle, the shaft that carries a door handle through the lock, and a keyhole should fall, before the hardware itself is fitted. Boring pilot holes for nails with a bradawl helps avoid splits, which spoil the look of the work. After a screw or nail's position is marked with a bradawl, the awl is withdrawn and replaced with a correctly sized brad. A centre punch, a pointed tool struck with a hammer to start a hole, can sometimes be used in its place, though a bradawl or other pointed tool is advised against for at least one task.

Layout work

A bradawl, or a similarly pointed tool, can help in general layout too. In panel and moulding assembly, it can slide wood slips toward a panel's centre before a moulding is driven down. In dowel-joint layout worked from a template, a thin pattern marking the joint's centres, a needle-pointed bradawl can prick the dowel-hole centres through the template before they are bored with twist bits, drill bits with a helical, screw-like cutting edge. In arch and doorhead layout, boring bradawl holes square from the bottom edge at marked jamb points, the sides of the opening, gives the radii needed for a soffit's layout, and a bradawl set at marked points can act as a pivot for drawing the curves of an arch's voussoirs, the wedge-shaped segments that together form the arch.

Finishing touches

Before boring a hole in polished hardwood, or in stained or varnished softwood, raising a small chip with the bradawl first lets that chip be glued back afterward to cover the hole. Scoring a tenon's sides with a bradawl, the tongue-shaped end of a joint that fits into a matching socket, gives excess glue somewhere to escape so its shoulders seat tightly. Compared with thin wood strips or knife-cut veneer, packing paper is less likely to split as a screw or bradawl is driven into it.