Overview
A lock is a device released by a key or other secret; Wikipedia's lock entry notes that keys are made of brass, plated brass, nickel silver or steel. A furniture lock secures a door, drawer or chest lid. It is kept distinct from a latch, which only holds a part shut (a lock may include a latch). Keyholes are usually finished with an escutcheon (see Escutcheon (keyhole plate)).
Types and sizes
- Cam lock: a barrel with a turning cam, through a drilled hole of about 16 to 19 mm (5/8 to 3/4 in); for drawers, flaps and small doors.
- Mortise lock: a rectangular case let into the door edge, with a bolt that engages a strike on the frame; the traditional furniture lock.
- Rim lock: a surface-fixed case on the inside face; on cupboards and chests.
- Chest lock: a case let into the lid front, with a catch plate on the box.
- Case sizes run from 50 mm (2 in) on small chests to 125 mm (5 in) on large cupboards.
Where it is used
Case pieces and chests of the Federal, Queen Anne and Pennsylvania German styles, with brass escutcheons and iron or brass locks; Biedermeier work used keyhole escutcheons instead of pulls; Japanese chests used large lock plates.
Choosing and sizing
Match the lock type to the door: cam locks for modern drawers, mortise for hinged doors, chest locks for lids. Check the backset and the key length. Choose a lock from a maker who gives mortise dimensions in a template. Fit the key early to test the action.
Installation
- Mark the keyhole centre and the case outline from the template.
- Drill the key hole and chop or rout the mortise to the case depth; clean the corners square.
- Fit the lock, then the escutcheon, and mark the strike position from the bolt with chalk or lipstick.
- Cut the strike mortise in the frame or box, and test the bolt throw.
- Screw the face plate with brass screws to avoid stains.
Wood movement and species
A lock in a solid door or lid must allow for seasonal movement: the bolt and strike need about 1.5 mm (1/16 in) of play. A mortise lock in a stile weakens it; the stile should be at least 45 mm (1-3/4 in) wide. Iron or steel cases in tannin-rich oaks (White oak, Red oak) stain the wood, so seal and use brass; rubbing the mortise with Dewaxed shellac helps.
Common mistakes
- Mortise cut too deep: the lock sits proud or the door face blows out.
- Strike aligned in winter and binding in summer.
- Key hole drilled off-line: the escutcheon will not cover it.
Related
- Escutcheon (keyhole plate): finishes the keyhole.
- Strap hinge: the traditional chest partner.
- Turn button: a simple non-locking catch.
Styles it suits
Suitable for
Fixes into: hardwood, softwood.
Poor choice in
The reasons are in the wood movement and species section above.
In our designs
Our example designs model this as DoorLock, ChestLock.
Sources
Updated 2026-10-03. Sizes and ratings are typical trade figures drawn from the sources above. A load rating is the maker's rating for one product, not a property of the type: check the maker's own sheet, and test a fit on scrap before cutting good wood.