uPVC Lock - Davis Locksmiths


Upvc/Double glazed doors are particularly vulnerable to attack recent articles in the National press have highlighted this problem and this issue has now become common knowledge.
Burglars can and are simply removing the cylinders fitted to these types of doors with basic everyday tools.

Mul-T-Lock has overcome this problem with the “Break Secure Cylinder” a simple to fit and economical way of ensuring this type of crime does not happen to you.

All our Mul-T-Lock break secure cylinders are supplied with 2 keys and security card for future key requirements.


Follow the “measuring guide” to ascertain the cylinder size, email us your requirements using the email banner at the bottom of the page.
You will then receive a quotation and payment instructions, once
confirmation of payment is received your order will be sent same day via recorded delivery.



1, Open the door

2, There is a long metal strip running the length of the door measure from the centre of this strip to the end of the lock both inside and outside,

“Example”  35mm x 45mm

3, Order your new “Mul-T-Lock break secure cylinder”


4, The metal strip running the length of the door has a screw in line with the bottom of the cylinder, remove this screw.

5, Insert the key into the cylinder and turn to either 11 O’clock or 1 O’clock depending on which side of the door you are working on, you will feel the cylinder move when the key is turned simply pull the cylinder out.

6, Insert the key into your new “Mul-T-Lock break secure cylinder” turn the key so the black cam is not protruding outside the cylinder and slide into the lock.

7, Put the screw back in

8, Test the lock from inside and outside to ensure correct operation.

The diagram below shows a cylinder which will help you to measure your lock should you encounter any difficulties.

uPVC Lock - MulTLock - Davis Locksmiths