The Pin Tumbler System

Most UNION locks with pin tumbler cylinders are supplied individually keyed.

To provide extra convenience and security, specially keyed systems have been developed to enable the customer to control those locks which an individual is authorised to operate. Specially keyed systems range from simple keyed-alike groups of locks operated by one key, to the more complex grand Masterkeyed systems where many groups of locks are operated by one key. A brief outline of the various systems is given here. Each system is specially designed to cover a number of important requirements such as security, convenience and rapid access to an area by night watchmen, fire brigade and other authorised personnel in the case of an emergency.

For further informaion on Masterkeying please go to our Masterkeying section.

 The Principle of the Pin Tumbler System

	A standard pin tumbler cylinder with the key removed, showing the drivers held in their locking position across the splitline between plug and cylinder.
	The same cylinder with the correct key inserted, showing pin-breaks aligned with the splitline between plug and cylinder, allowing the key to be turned.
	The same cylinder with an incorrect key inserted showing the pin-breaks misaligned with the splitline, preventing the key from being turned.