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Euro cylinders - What are they?

Simon G • October 4, 2019

What are euro cylinders and what do they do?

Euro cylinder locksmith London

A Euro Cylinder lock or pin tumbler lock, which was its original description when 1st patented in 1805, is used primarily as a locking medium to operate a lock case with a euro shaped hole.The standard Euro Cylinder is the most common cylinder lock available widely from DIY stores including the majors plus high street shops specialist retailers and locksmiths.

The Euro Cylinder is located through the lock case and secured by a fixing screw through the face of the lock case. The key rotates a cam which in turn drives the deadbolt in the lock case into a prepared keep in the frame of the door thus securing the door in place. Or in the case of UPVC doors, will activate the mechanism inside the door and not allow the handle to go down.

Euro Profile cylinder locks are by far the most popular means of locking todays modern homes and very many commercial sites including schools academies and hospitals to name a few. Euro Cylinders are very versatile hence their popularity amongst Locksmiths and Architectural Ironmongers. They can also easily be equipped with Thumbturns that can operate the cylinder from within - without the need for a key, safe to escape in case of a fire. (BS 3621/PAS 3621)

Typically the Euro Profile Cylinder or Lock Barrel as it is sometimes referred come in a variety of lengths typically 35mm to 40mm for single or half Euro Cylinder locks and 70mm up to 120mm as standard length Euro Cylinders in equal lengths either side of the central cam, for example a 70mm length standard Euro Profile Cylinder lock will measure 35mm either side of the operating cam . And an 80mm will be 40mm either side of the cam and so on. There also sizes that come in odd, a 90mm cylinder can be 40mm one side and 50mm the other, these typically come in UPVC doors.


Euro Lock types

So we have Anti Drill Euro Cylinders and anti drill and anti pick Euro Cylinders. Keen to be one step ahead of those seeking to burgle us the industry introduced British Standards to encourage manufacturers of Euro Cylinder Locks to improve not only their reliability but also its actual security level. CE marked is a necessity to prove the product is fit for function, however BSI Kitemarked products have been through additional tests ensuring locks can stand up to common forms of attack.

This standard ensures minimum levels of reliability and degrees of security depending on the standard achieved during testing.

The latest level of cylinder security is the British Standard Kite Mark TS* cylinders rated 1-3. 1 being the basic level and 3 at the time of writing being the highest level. A 3 star cylinder now offers, Anti Drill; Anti Pick; Anti Bump and Anti Snap. This does not however guarantee key security as some of the manufacturers have made their Kite Marked Euro Profile cylinders on a standard keyway where key blanks are available a key bars and locksmiths. However most will also come with patented keyways thus ensuring you are the only holder of the keys.

Parts of a Euro cylinder

  • Core(s) – As with most locks in London the keyways are often quite restrictive. Often they have paracentric keyways, which means that the wards on face extend past the center of the keyway. On the other hand, some have very wide rectangular keyways. Cylinder locks do not have particular internal mechanisms. The cores often have pin tumbler or dimple configurations, but there are exceptions.
  • Revolving Cam – They are often made of a hard plastic or metal. An actuator or cam is a rotating piece on the lock that the key manipulates. The cam, in turn, moves the lock bolt or activate the mechanism. Some euro profiles are even designed to only work on one side at a time, so two people cannot open the lock simultaneously. Too much pressure or wear can damage the cam. If the cam slips, that means that it is misaligned, so that the key is retained while trying to lock it. Technically the device might lock, but it will need to be unlocked to remove the key.
  • Fixing Hole – A gap that allows the cylinder to be fastened inside the door. The fixing screw is inserted into the door with the lock in place, and this secures the device. This gap in the metal of the lock comprises the strength of the lock as well as secure it in place. When it is pressured this perforation will cause the lock to fail.
  • Lock Body – On the Euro profile, there is a rectangular gap in the body where the cam is placed. Two C-clips keep the cam in position. This gap, along with the fixing hole leaves very little metal remaining to keep the device together. The gap separates two different cores that can be keyed alike or differently.
  • High Security Additions – These can include sacrificial weak points, stainless steel pins (anti drill protection), etc. Anti-snap cuts do not truly prevent snapping. What they do is provide sacrificial points where the device can snap and leave enough of the lock in working order, so the security is not compromised. Anti-drill protection can often include a spinning disk on the front to prevent the drill bit gaining traction.

Weaknesses that may occur in a euro cylinder

Lock Snapping

We give a longer breakdown of the process here. In short simply access the protruding end of a Euro cylinder and grip it with a tool or mole grips. Shake the lock until it snaps in half. Remove the lock. Access the mechanism or case and open the door. The weak point in Euro Cylinders is the metal right beneath the fixing hole. Exerting severe pressure on the cylinder will break the lock in half. Once the lock is broken, the door can be opened very easily.

The best way to prevent snapping is by buying anti-snap locks or by having the cylinder flush against the door. If it is at all protruding the lock can be snapped. That is the reason for the term “lock snapping”. With anti-snap cylinders the lock will snap in a way that does not compromise the lock’s security and keeps the cam covered by at least half the pins. All BSI Kitemarked cylinders that are up to date will provide anti snap features.

Drilling a euro cylinder

Be careful if you choose to drill these types of locks. If you drill too far into the lock you will break the actuator. Once the actuator is broken, the lock will not work, even with the key. Once the actuator is broken the lock will need to be removed. This will be quite difficult if the lock is anti-snap. If the lock cannot be snapped, and the actuator has broken, the price of getting into the house compounds with the price of installing a new door. Drilling a lock is always the last resort, whoever is drilling the lock needs to keep a count of how many pins they are hitting.


If you need to contact a locksmith for more advice just head here.

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