Euro Cylinder Replacement Sheffield Thumbturn Cylinders

Lost keys, a stiff barrel or a cylinder that sticks out past the handle? We measure from the cam, fit the correct size and can put every door on one key.

Call 0114 463 0063 See prices

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Sized from the cam

Each side measured so the cylinder sits within a few mm of the handle

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Thumbturn or double key

Key outside with a turn knob inside, or a key on both sides

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Keyed alike sets

Front, back and garage side door cylinders opened by one key

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Quick swap

A like for like cylinder change is usually done in minutes once we arrive

We carry out euro cylinder replacement across Sheffield from £20, fitting a correctly sized single, double or thumbturn cylinder to uPVC, composite, aluminium and timber doors, usually arriving within 25 to 45 minutes. A euro cylinder is the barrel your key goes into on most modern doors, and changing it gives you new keys without touching the rest of the lock.

This page explains how cylinders are measured, which type suits your household, and when a standard cylinder is fine and when an anti snap one is worth paying for.

By the Sheffield Locksmith 24H team, 45 Broughton Lane, Sheffield S9. Updated 13 October 2026.

The euro cylinder: a small part that controls the whole door

Look at the keyhole on a uPVC or composite front door and you will see the end of a euro profile cylinder: a round top with a narrower tail beneath it. It slides through the lock case inside the door and is held by one long fixing screw on the edge of the door. In the middle is a rotating cam that throws the locking mechanism when the key turns.

That design is why the cylinder is so easy to change. Undo one screw, turn the cam to the right position and the old barrel slides out. The multipoint mechanism, the handles and the door itself stay exactly as they are. If the hooks or bolts in the door edge are the problem rather than the barrel, that is a job for our multipoint lock repair service instead.

You will also find euro cylinders in some timber doors with euro profile sashlocks, in aluminium shop and bifold doors, and in many garage side doors.

How a euro cylinder is measured

Cylinders are sold by two numbers: the length from the centre of the cam to the outside end, and from the centre of the cam to the inside end. A cylinder described as 35/45 is 35mm on one side and 45mm on the other, 80mm overall. Doors are rarely symmetrical, so offset sizes like 40/50 or 35/55 are common.

Find the fixing screw. It is on the edge of the door, in line with the keyhole. Its centre marks the cam position.
Measure each side. From that screw centre to the outer face of the cylinder, then to the inner face.
Check how far it protrudes. Ideally no more than about 3mm beyond the handle or escutcheon on the outside.
Note the door thickness. Composite doors are often thicker than uPVC ones, so a size that fits one will be too short for the other.

A cylinder that stands well proud of the handle is easier to grip and attack. Getting the size right is as important as the brand, which is why we measure on site before fitting rather than guessing from the old one.

Single, double or thumbturn cylinder: which suits your home?

Double cylinder

Key on both sides. The door cannot be opened from inside without the key, which helps if there is glass near the lock that someone could break and reach through.

From £25. Keep a key near the door at night so you can get out.

Thumbturn cylinder

Key outside, a small turn knob inside. Anyone indoors can lock and open the door without a key, which many families with young children and older relatives prefer for getting out quickly.

Priced on the phone; avoid if the knob can be reached through a letterbox or glass panel.

Single (half) cylinder

Key on one side only, a blank on the other. Used on garage side doors, gates and some commercial doors where the inside never needs a key.

Less common on homes.

In shared houses and flats, fire safety rules may say how exit doors should open from inside. If you are a landlord, your fire risk assessment or the council’s licensing conditions should guide whether a thumbturn or a keyless egress lock is expected. We can fit either, but we will not tell you what your licence requires; check that first.

One key for every door: keyed alike cylinders

Most houses end up with a bunch of keys that all look the same: front door, back door, conservatory, garage side door. Keyed alike cylinders are made in matched sets so a single key works every one of them, each cut to its own size.

It saves fumbling in the dark and means a lost key only needs one set replaced. It also helps people who struggle with keys, as there is no choosing between them. The cylinders must come from the same manufacturer and series, so the set is ordered or selected to suit the doors, usually after a photo or a quick visit. If you only have one cylinder to change and want it to match keys you already use, tell us the brand stamped on the key and we will see whether a matching cylinder is available.

Standard cylinder or anti snap upgrade?

A standard euro cylinder from £20 is a like for like swap. It restores smooth operation and gives you new keys, which is what most people need after lost keys or a stiff barrel. It does not add security beyond what the door had before.

Front and back doors facing a street, alley or open garden are where an upgrade earns its keep. A cylinder rated TS007 3 star or Sold Secure Diamond is built to resist forced attack, and our high security lock installation starts from £120. The anti snap locks page compares the ratings in detail, and our guide on the benefits of upgrading to anti snap cylinders helps you decide which doors to do first. Internal doors, sheds and side gates rarely need the premium option.

Signs your euro cylinder needs replacing

What you notice	Likely cause	Usual answer
Key goes in but is gritty or stiff	Worn pins or dirt in the barrel	Replace the cylinder
Key turns all the way round with no effect	Broken cam or failed gearbox	Check the cam first, then the mechanism
Key only turns with the handle lifted hard	Door alignment, not the barrel	Adjust the door or keeps
Cylinder wobbles or sticks out	Wrong size or loose fixing screw	Fit the correct size
Keys lost, stolen or not all returned	Nothing wrong mechanically	New cylinder and keys

If the key will not turn at all, avoid forcing it, as a snapped key makes things harder. A door that will not lock even with a new barrel is covered on our uPVC door not locking page.

Oval, rim and other cylinder types we replace

Not every barrel is euro profile. Oval cylinders, from £25, have a smooth oval body and turn up in some older timber and imported doors. Rim cylinders, from £20, work with surface mounted nightlatches and sit on the outside face of the door. We identify the profile when we arrive and carry common sizes of each, so you are not left waiting for a part in most cases. Wider lock changes, including mortice locks and full mechanisms, are listed under our locksmith services and on our price list.

Euro cylinder replacement prices

Starting prices to change each type; the exact cylinder and total are confirmed before we begin.

Service	Starting price	Notes
Euro cylinder	from £20	Like for like barrel sized to your door, new keys supplied
Double cylinder	from £25	Key operated on both sides
Oval cylinder	from £25	For doors using the oval profile
Rim cylinder	from £20	For surface mounted nightlatches
High security lock installation	from £120	TS007 3 star or Diamond rated anti snap cylinder fitted
uPVC door lock repair or replacement	from £20	If the mechanism behind the cylinder also needs attention

Starting prices, confirmed on the phone before any work begins. See the full Sheffield locksmith price list.

Questions and Answers

How much does it cost to replace a euro cylinder lock?

A standard euro cylinder replacement with us starts from £20, a double cylinder from £25 and a high security anti snap cylinder from £120 fitted. We confirm the starting price on the phone before setting off.

What does 35/45 mean on a euro cylinder?

It is the length in millimetres from the centre of the cam to each end. A 35/45 cylinder is 35mm on one side and 45mm on the other. The longer side normally goes inside so the outside sits flush with the handle.

Are thumbturn locks safe?

They are safe on most doors and make it easy to get out in an emergency. The risk is a thumbturn that can be reached through a letterbox, cat flap or nearby glass. In those cases a letterbox guard or a double cylinder is the better choice.

Can I change a euro cylinder myself?

Many people do, as it only involves one fixing screw. The common mistakes are buying the wrong size, which leaves the barrel sticking out, and forgetting to set the cam position, so the new one will not slide in. If in doubt, measure twice before ordering.

Do I need to replace the whole uPVC lock if I lose my keys?

No. Swapping the euro cylinder gives you new keys and leaves the multipoint mechanism in place. It is the quickest and cheapest way to secure a door after lost or stolen keys.

Can all my doors use the same key?

Yes, if the cylinders are fitted as a keyed alike set from the same range. We size each one to its door so a single key works throughout. Landlords sometimes ask for a master key system instead, which gives different tenants different keys.