This European standard applies to cylinders for such locks as are normally used in buildings and are designed to be used with cylinders. It identifies one category of use grade, three grades of durability, three grades of fire resistance, four grades of corrosion and temperature resistance, six grades of key security, and five grades of attack resistance.

Cross-keying is a term that is used to describe a cylinder that is operated by more than one change key. This is different than a master keyed cylinder because usually a cylinder that is master keyed will only be operated by one change key as well as the master key.

What is master key? A master key is a key which will open all the locks in a set, even though each lock has its own different key.

The mortise lock is a very popular and ancient design that has stood the test of time. They are sturdy and reliable. Their structures are also relatively diverse. Modern mortise locks are a popular lock often used in the security industry of commercial locksmiths. Its rugged design has stood the test of time. Mortise locks can be used for decades. In fact, these mortises exist in old houses and buildings and are resistant to bad weather and time. The mortise lock has a long life, so understanding the structure and principle of the mortise lock can provide great help for installation and maintenance.