Abrace is ahand tool used with a bit (drill bit orauger) todrill holes, usually inwood. Pressure is applied to the top while the handle is rotated. If the bit's lead and cutting spurs are both in good working order, the user should not have to apply any pressure other than for balance: the lead will pull the bit through the wood. Bits used to come in a variety of types but the more commonly used Ridgeway and Irwin-pattern bits also rely on a tip called a snail, which is a tapered threaded screw that pulls the bit forward.

The U-shaped handle is acrank. It gives the brace much greatertorque than other kinds of hand-powered drills. Abrace and bit can be used to drill wider and deeper holes than can a geared hand-powered drill. The cost of the greater torque is lower rotational speed; it is easy for a geared hand drill to achieve a rotational speed of several hundredrevolutions per minute, while it would require considerable effort to achieve even 100 rpm with a brace.

The front of the brace consists of achuck spindle withV-shaped brackets orclamps inside. Turning the spindle of the chuck in a clockwise direction tightens thedrill bit in the chuck; turning counterclockwise loosens the bit for removal.

In most modern braces, immediately behind the chuck is a three positiongear release that allowsratcheting of the handle when in tight spots. Turning the gear release from the center position allows ratcheting the brace in the required direction. Turning the gear release fully clockwise lets it remove wood in a clockwise direction with the ratchet action going counterclockwise. Placing the gear release fully counterclockwise allows turning the brace and bit in a counterclockwise direction, usually to remove the drill bit from the hole. The center position of the gear release prohibits the ratcheting effect.

The U-shaped crank has a wooden spindle on it and—along with the top spindle—is allowed to freely turn under the hands without stressing the hands, thus preventingblisters.

The earliest carpenter's braces equipped with a U-shaped grip, that is with acompound crank, appeared between 1420 and 1430 inFlanders.^[1]

The brace has other names. Bit brace is the most often used name, but Carpenter's brace, ratchet brace (if a ratchet mechanism is incorporated into the design), and swing brace are also commonly used.

Hand drills for some related tools, including the type sometimes known as a wheel brace.

• Adamson, John, "The Ultimatum brace: a feat of engineering",Furniture & Cabinetmaking, issue 264, December 2017, pp. 52–5
• Eaton, Reg (1989).The Ultimate Brace: A Unique Product of Victorian Sheffield. King's Lynn: Erica Jane PublishingISBN 978-0-9514695-0-7OCLC 21348455
• Russell, David R., with Robert Lesage and photographs byJames Austin, cataloguing assisted by Peter Hackett (2010).Antique Woodworking Tools: Their Craftsmanship from the Earliest Times to the Twentieth Century Cambridge:John AdamsonISBN 978-1-898565-05-5, "Boring tools: drills and braces", pp. 459–90
• White, Lynn Jr. (1962),Medieval Technology and Social Change, Oxford: At the Clarendon Press