Measurement and Choice of Locks

How do we define which type of lock should be used for a specific door?

In most cases it is sufficient to measure the locking device, or a lock/cylinder/padlock installed on a specific door. Below you will find information on how to define the size and type of locking device, with division into product groups.

Cylinder locks

The size of a cylinder consists of 2 elements, for example 30/30. It means that the distance between the face of the cylinder and the middle of the mounting screw hole is 30 mm and the distance between the middle of the mounting screw hole and the second face is also 30 mm. The sizes of the cylinders range from 30 mm, with each next one 5mm bigger than the one before. From the safety point of view it is vital that the cylinder does not protrude by more than 3 mm beyond the escutcheon. If the cylinder is to be equipped with a knob, we must also define at which dimension this knob is to be installed, for example by adding the letter "G" next to the specific dimension - cylinder G30/35 (knob at dimension 30).

The cylinder is installed by removing the mounting screw, extracting the old cylinder, introducing the new one and re-installing the mounting screw. In order to install and remove a cylinder we need to have the key to this cylinder in order to shift the slider. The slider is normally set in the 7 hour position and prevents the installation or removal of cylinder without the use of the key.

The LOB product range contains various cylinder platforms. The following cylinders are dedicated to Master Key systems: Comfort, Comfort Plus and Dragon. Our cylinder locks have all adequate test documentation and certification issued by the Institute of Precision Engineering and by the Building Research Institute. The LOB product range also includes a special tool for the measurement of the length of door locks.


The most important dimensions of a padlock are the size of its body, thickness of the shackle and the gap between the body and the shackle.

When choosing a padlock one must also consider the conditions in which it is going to operate. The LOB product range includes padlocks suitable for operation in variable atmospheric conditions. Such padlocks are equipped with appropriately installed seals that protect the mechanism against moisture.

LOB also offers burglar-proof padlocks characterized by safety grades certified via appropriate certificates by the Institute of Precision Engineering in Warsaw. When choosing a padlock, one must also take into consideration its planned location. If the gate or staples are too weak, any potential burglar will be able to break them away together with the padlock. Therefore we recommend the use of an anti-burglar padlock equipped with hasps (guards), which effectively block the access to the shackle. This kind of protection is ideal for the protection of our property against burglary.

Rim locks

A rim lock is mainly characterized by two dimensions. These are the spacing between the mounting screws and the distance between the middle of lock/knob and the face of lock, which should be mounted flush with the door edge. At LOB there are two standards: 50 mm and 60 mm for single-bolt locks. The range of LOB products includes standard as well as certified rim locks. 

Cam locks

Cam locks are designed for various types of cases, furniture, cupboards, containers, etc. The key element here is the diameter of the hole for the installation and clamping of the lock with a mounting ring and the length of the cam (lock). The length of the cam (lock) is important, because it blocks the door/cover and must have enough space for operation.

Locks with additional vertical locking, with casement bolts/tendons are also available. These locks are designed mainly for mounting on cupboard doors. LOB products include two cam locks that can be included in the Master Key system - ZKT21 and the casement bolt ZKT31 lock.