• Cylinder locks

    Euro profile locks, an example of a cylinder lock. These are commonly found on uPVC doors and commercial buildings where re-keying doors is common.

    Commonly pin tumbler locks are found in a cylinder that can be easily unscrewed by a locksmith to facilitate rekeying. The first main advantage to a cylinder lock, also known as a profile cylinder lock or euro, is that the cylinder can be changed without altering the boltwork hardware. Removing the cylinder typically requires only loosening a set screw, then sliding the cylinder from the boltwork. The second is that it is usually possible to obtain, from various lock manufacturers, 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 nightlatchesdeadbolts and roller door locks.

    Typically, commercial padlocks can also be included, although these rarely have removable cylinders. Standardised types of cylinder include:

    • rim-mounted (also known as night latch) cylinders
    • Euro cylinders
    • key-in-knobset cylinders
    • Ingersoll-format cylinders
    • American, and Scandinavian round mortise cylinders
    • 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

    Other varieties

    tubular pin tumbler lock is a pin-tumbler lock with a round keyway.

    A dimple lock is a pin tumbler lock where the bitting is located on the side of the key, rather than the top.

    Master keying

    master-keyed lock is a variation of the pin tumbler lock that allows the lock to be opened with two (or more) different keys. This type is often used for doorlocks in commercial buildings with multiple tenants, such as office buildings, hotels, student accommodation and storage facilities. Each tenant is given a key that only unlocks their own door, called the change key, but the second key is the master key, which unlocks all the doors, and is usually kept by the building manager, so they can enter any room in the building.

    In a master-keyed lock, some or all of the shaft hole in the lock have three pins in them instead of two. Between the driver pin and the key pin is a third pin called the spacer pin. Thus each pin line has two shear points, one where the driver and spacer pins meet, and one where the spacer and key pins meet. So the lock will open with two keys; one aligns the first set of shear points and the other aligns the second set of shear points. The locks are manufactured so one set of shear points is unique to each lock, while the second set is identical in all the locks. A more secure type of mechanism has two separate tumblers, each opened by one key.

    More complicated master-key lock systems are also made, with two or more levels of master keying, so there can be subordinate master keys that open only certain subsets of the locks, and a top-level master key that opens all the locks.


    Lock picking

    The basic pin tumbler lock alone is vulnerable to several lock picking methods, the most straightforward being lock bumping and snap guns. To combat this, many higher security cylinders incorporate the use of a variety of specialised pins, collectively known as security pins, that are designed to catch in the lock cylinder if a snap gun or bump key is used.

    Lock snapping[edit]

    In 2009, West Yorkshire saw the start of lock snapping which is a method of forced entry that certain types of cylinder locks are vulnerable to, such as the euro cylinder which are commonly found on uPVC doors in Europe Lock snapping involves applying a strong torque force to the lock cylinder, usually with a pair of locking pliers, thereby breaking the mechanism and allowing access to the latch. It can take between 50 seconds and 2 minutes to snap the lock and gain entry. Police in the UK have estimated that around 22 million doors throughout the country could be at risk from lock snapping.

    Lock snapping is possible when the lock has a weakness where the retaining bolt passes through a thinner part of the lock. A recent development is to build a lock with a front section that snaps off the main body, leaving enough of the mechanism behind to prevent access to the operating latch. Some designs feature more than one sacrificial section which can stop the door from being opened from the attacked side (even with the key) while allowing the door to be opened from the other side.

    Blowtorch burglary

    Criminals utilise a small blow torch to target the area of uPVC or composite material surrounding the euro lock and door handle. The reason for this is to create a hole deep enough to reach deep into the door concentrating on the euro lock area. The goal once having created the hole is to reach with mole grips deep past any sacrificial lines of an inferior euro cylinder lock. The weak point of any euro lock is the centre screw hole which essentially holds the lock in place but also above this centre screw hole is the euro locks cam switch which is the switch that locks and unlocks your door. Once past the initial sacrificial lines of the euro lock, the burglar applies pressure to the screw hole area located in the centre of the cylinder lock, which then breaks easily as per a standard lock snapping method.

    Protection against vulnerabilities

    Cylinders that meet either Sold Secure SS312 Diamond or TS007 3 Star standard will protect against drilling, picking, bumping, snapping, and plug extraction methods of attack. Such cylinders are preferably fitted in conjunction with a high-security mechanism and handle set.