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Note added at 10 mins (2008-07-18 16:59:09 GMT)
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A cylinder lock is a lock in constructed with a cylinder that a locksmith can easily unscrew to facilitate rekeying.[1] The cylinder may contain any of a variety of locking mechanisms, including the pin tumbler lock, the wafer tumbler lock and the disc tumbler lock.
The first main advantage to a cylinder lock is that the cylinder may be changed without altering the boltwork. Removing the cylinder typically requires only loosening a set screw, then unscrewing the cylinder from the boltwork. The second is that it is usually possible to obtain, from a lock manufacturer, cylinders in different formats that can all be used with the same type of key. This allows the user to have keyed-alike, and master-keyed systems that incorporate a wide variety of different types of lock, such as nightlatches, deadbolts and roller door locks. Typically, padlocks can also be included, although these rarely have removable cylinders.
Standardised types of cylinder include key-in-knobset cylinders, rim (also known as nightlatch) cylinders, Ingersoll format cylinders, American, and Scandinavian round mortise cylinders, and Scandinavian oval cylinders. There are also standardised cross-sectional profiles for lock cylinders that may vary in length - for example to suit different door thicknesses. These profiles include the europrofile (or DIN standard), the British oval profile and the Swiss profile.
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