How to Measure & Inset: Full Mortise Locks
Realize the Benefits and Uses of Full Mortise Locks
Full Mortise Locks deliver a seamless, integrated look for fine furniture and cabinetry. The mechanism sits entirely within the wood, leaving only an a simple brass faceplate visible. They are perfect for drawers and doors where aesthetics matter. Installation does require routing a pocket into the wood to accommodate the lock body. Once installed, the appearance is refined and uncluttered complementing the quality craftsmanship of the furniture.
USE ON DRAWERS, DOORS AND DESKS.
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Drawer LocksConsider keyhole location carefully—it's typically off-center with this style lock. When locked, the bolt extends upward into the cabinet body above, securing the drawer firmly in place. A strike plate is seldom necessary with this design, simplifying installation while maintaining reliable security. Door LocksDoor orientation matters when selecting a lock—verify whether you need right-hand or left-hand operation. Our full mortise locks are versatile enough to work with both configurations, so you can outfit your cabinet doors with confidence regardless of swing direction.
Desk LocksThe most used full mortise locks for desks are the popular roll top desk locks. These applications require a trap-door strike with the lock. |
New Construction

- Consider placement of keyhole cover on drawer, chest or box as this could affect actual keyhole location
- Keyhole location determines required backset measurement for lock.
- Backset: distance between selvedge-edge of lock to center-of-pin in keyhole. (see diagram above)
Replacing locks:
- If you have original lock: measure distance between top edge of lock to lock pin in center of keyhole. This measurement is known as the backset.
- If old lock not available, determine backset by measuring: distance from center of keyhole (where lock pin will be) to top-edge of drawer / box or side-edge of door.
- The backset measurement of the replacement lock, must match backset measurement in original lock and/or keyhole location measurement in drawer, box or cabinet door.
FULL MORTISE INSTALLATION
Determine desired location of lock
- Adjust position to allow for location of keyhole as it is often off center in lock
- Lock should be positioned in middle of wood thickness, providing a wood edge around selvedge
- Mark location of lock-selvedge on door or drawer edge
- Hold lock-selvedge, at desired location, on wood thickness and trace outline
- Inspect outline for accuracy , straighten lines where necessary
- Mortise Selvedge
Lock-body
- Trace lock-body outline into selvedge-mortise at correct position
- Cut lock-body-mortise
- Mortise can be slightly off as selvedge will conceal lock-body once installed.
- Check lock with mortise, lock should sit in mortise with selvedge flush with wood surface
- Strikes are rarely use with reproduction full mortise locks. Traditionally a simple mortise was cut in the wood to accept the lock bolt.
Keyhole Placement
- Measure distance from top of lock-plate to center of key pin
- Measure distance from side of lock-plate to center of key pin
- With these two measurements locate keyhole on furniture front, make sure key pin is aligned with keyhole location
- Drill small pilot hole at key pin location, hold lock in position and check to make sure hole lines up with key pin
- Drill hole larger to accommodate key barrel
Mount Lock
- Mount lock in a mortised- pocket in wood thickness/edge
- Selvedge edge should be level with top of drawer or edge of door
- Attach with wood screws
- For a finished appearance: mount an escutcheon/keyhole plate, on furniture front.




