Mortise locks
A mortise lock is fitted inside the door and determines how it closes or locks. Choose a passage lock for free access, a bathroom mortise lock for privacy, or a lock operated with a key or cylinder. Compare the backset, faceplate, and center-to-center distance with the existing cutout and hardware before ordering.
What is a mortice lock?
A mortice lock is the locking mechanism installed in a recess in the door. The faceplate remains visible on the side; the handle and any locking mechanism are located on the door surface. The lock type determines whether the door simply stays closed or can also be locked with a key, cylinder or WC operation.
Therefore, choose the desired function first. A freely accessible passage requires a different mechanism than privacy in the bathroom. Only then should you compare the dimensions and the colour of the faceplate.
Four types of mortice locks side by side
The product names may look similar, but the operation differs. A latch lock without locking is not the same as a lock with a keyhole. Use the stated function and specifications to select the right version.
| Lock type | Operation | Suitable application |
|---|---|---|
| Latch lock | Handle, without locking | Freely accessible passage |
| Lever tumbler lock | Bit key | Door with traditional key operation |
| WC mortice lock | Matching WC furniture | Toilet or bathroom door |
| Cylinder mortice lock | Matching profile cylinder | Door with cylinder operation |
Backset, centres distance and faceplate
The backset is the distance from the front edge of the faceplate to the centre of the spindle or cylinder axis, according to the dimension drawing. The centres distance describes the distance between the handle and the locking mechanism. In addition, the height, width and shape of the faceplate must fit the door.
Carefully measure the existing situation and also compare the depth of the lock case. A difference of just a few millimetres may mean that a recess or the fittings do not align. Do not use measurements from a similar colour variant unless they have been confirmed for the selected product.
Installation, use and maintenance
- Choose the lock based on its function, then compare the complete dimensional drawing.
- Check whether the latch bolt is suitable for the door's handing or can be reversed.
- Align the position of the strike plate in the frame with the lock operation.
- Test the latch bolt and locking mechanism with the door open first, and do not force a stiff mechanism.
Buying mortise locks at WDTegels
At WDTegels, you can compare mortise locks for different door functions. Combine the selected model with suitable door handles and check the contents of the package. A cylinder, locking mechanism or strike plate is not automatically included; the product information is decisive here.
Frequently asked questions
How do I know which mortise lock I need?
First determine whether the door needs to remain freely accessible, be lockable with a key, or require bathroom turn-and-release hardware. Then compare the dimensions of the existing lock and cutout with those of the new version.
What is the difference between backset and center distance?
The backset is measured from the faceplate toward the spindle. The center distance is the distance between the spindle and the axis of the key, cylinder or bathroom turn-and-release. Check the dimensional drawing for the exact measurement points.
Can I replace a mortise lock without modifying the door?
Only if the lock case, faceplate, dimensions and mounting match. Also check the position of the strike plate. The same product name is not enough to determine compatibility.
Is every mortise lock suitable for an exterior door?
No. Use only a lock that is demonstrably suitable for the application and the complete door construction. The presence of a cylinder opening alone says nothing about that suitability.
