Replace a lock cylinder


In rare cases, it may be necessary to change the lock cylinder of a door lock. For the correct replacement of a door lock you need basic knowledge about the function of a lock cylinder, good preparation and suitable tools. Below you will find detailed instructions so that you can exchange a lock cylinder quickly and easily.

Construction of lock cylinders and locks

Before you get started with replacing the lock cylinder, you should familiarize yourself with the various technical designs and operating principles.

  • Warded locks
  • Stiftschlösser (with mortise locks)
  • cylinder locks

In particular, pin and cylinder locks are strongly fused together because of their frequent use. Thus, a cylinder lock may well have a pen filling, which can sometimes even be exchanged.

For every security requirement, the right lock cylinder

Basically, the increased complexity and thus the safety of the lock cylinder increases with increased security requirements. For example, Buntbartschlösser are often found on room doors, while basement and front doors are at least secured with cylinder locks, but more and more frequently with pin locks.

You do not have to remove the old lock cylinder immediately

The expansion of the two lock cylinder types is the same. However, pin lock cylinders can be designed as security locks whose replacement is subject to conditions. You also do not need to remove a cylinder lock if you do not have a replacement lock (as a sample, for example). You can also determine the necessary dimensions when installed.

Step-by-step instructions for replacing a lock cylinder

  • lock cylinder
  • possibly rust remover
  • Screwdriver (mostly cross)
  • Angle with units of measure
  • alternatively calipers (calipers)
  • possibly a small hammer
  • in the case of a hammer, a screwdriver suitable for use with a hammer
  • Key of the old lock cylinder

1. Preparatory work

As already mentioned, you can take the dimensions of the lock cylinder before removing it.

a) measuring the lock cylinder
Open the door. On the front side you see a slight downward offset to the cylinder lock a screw. This screw fixes the lock cylinder. Starting from the center point of this screw, measure the lock cylinder to the right, then from the tapped hole to the left.

Both dimensions do not have to be identical to each other. Finally, measure the lock cylinder from one (inner) to the other (outer) side of the bracket to confirm the total length. You can also determine the diameter of the circular lock cylinder.

b) Measuring the door fittings
Maybe the old door lock was not flush with the hardware. If you want to change this in the future or use seriously different fittings (in thickness), you should also measure the distance between the door fittings.

2. Remove and replace the old lock cylinder

Before you get the new lock cylinder, you can spray rust remover into the old cylinder. Straight doors to outdoor areas, but also very old doors in the interior can have corrosion, which is shown on the screwed and then possibly stuck fixing screws.

a) fixing screw and driver
Now that you have purchased a suitable locking cylinder, start to loosen this fixing screw. Since it is a fine thread, it takes a long time to feel the screws. Now put the key in the lock and turn it to the position 11 o'clock or 1 o'clock (approximately).

b) Troubleshooting when removing the fixing screw
Does not loosen the screw, put on the screw head with the screwdriver and perform a few, emotional hammer blows on the screwdriver handle end. By now, the screw should loosen.

c) Position the driver
Inside is the driver, who looks like a key-beard due to the same task. So that no unauthorized persons can exchange a lock, the key must be turned into the lock and as described. Only then does the driver make an escape with the lock, otherwise he locks.

d) Remove lock cylinder and replace
If necessary, shake something on the lock cylinder. If he is very tight, you can also perform sensitive hammer blows on the front side of the lock cylinder. Then pull out the old cylinder and insert the new lock cylinder. Again, the driver must be brought into alignment with the lock, then the fixing screw is attached.

Tips & Tricks

Security locks may not be changed easily. In residential complexes with locking systems, the consent of the landlord (in writing) must be obtained. Under certain circumstances, the switch to a non-safety-relevant lock cylinder can have a negative impact on existing insurance coverage.


Video Board: How to change a euro lock cylinder