Below is a list of commonly used terminology relating to the locksmith and security trades.

Name Description
Birmingham bar A Birmingham Bar is a strengthening device and is normally fitted on the inside of the house on the hinge side of the door frame.
BS3621 A British Safety Standard Kitemark relating to a 5 lever door lock specification that can be deadlocked and only opened with a key. Your insurer may specify this level or higher in relation to home or building insurance.
BS8621 A British Safety Standard Kitemark similar to that above except this one allows for single handed exit without the use of a key. Your insurer may specify this level or higher in relation to home or buildings insurance.
Deadlock

A type of lock requiring a key to open or lock it. If it is a single cylinder deadlock, it can only be opened by a key from one side. Whereas a double cylinder would be able to opened or locked from both sides.