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How to change a euro cylinder without leaving it proud

Updated: October 2026

The new euro cylinder is still in the packet. You can change it on a multipoint door if one screw comes out, the cam lines up, and the new barrel matches both sides of the old one. The job goes wrong when the outside sticks out, or when you ordered from one overall length. Profile and split are on the [lock cylinder buying guide](/hub/door-and-window-security/lock-cylinder/sub/lock-cylinder-buying-guide), and the ten listings are on the [lock cylinder comparison](/hub/door-and-window-security/lock-cylinder). Peter F. used those listings and public UK guidance in October 2026. A qualifying purchase can earn a commission at no extra cost to you.

The new euro cylinder is still in the packet. You can change it on a multipoint door if one screw comes out, the cam lines up, and the new barrel matches both sides of the old one.

Our top picks

greenteQ greenteQ Orion 35/35 thumbturn

Best overall

greenteQ greenteQ Orion 35/35 thumbturn
8.6/10about £32.06
View offer
Yale Yale rim cylinder

Rank 2

Yale Yale rim cylinder
7.4/10about £9.12
View offer
XFORT XFORT 50/50 euro cylinder

Best value

XFORT XFORT 50/50 euro cylinder
7.8/10about £13.99
View offer
On this page
  1. 1.Get the old cylinder out
  2. 2.Measure both sides, then order
  3. 3.The screw, the 3 mm line, and a test with the door open
  4. 4.When you stop and call a locksmith

Get the old cylinder out

Open the door and find the single fixing screw on the edge, in line with the cylinder. West Yorkshire Police’s euro-cylinder leaflet starts there: that screw out, then the key turned a little until the cylinder slides. Truly PVC’s fitting note puts that turn at about 25 degrees. You are lining the cam up with the slot, not forcing the barrel. If the key has sheared off flush, or the cam will not move, stop. Keep the door open the whole time. The best value, the XFORT 50/50, lists one screw. Wavanta and the Valorada 35/35 list two lengths, 60 mm and 75 mm. The top pick, greenteQ, lists screws, and reviewers still report them short on a thick door. Reuse the old screw only if it catches the far side and the thread is clean.

Measure both sides, then order

Measure the loose cylinder from the centre of the screw hole to each end. 35/35 is 70 mm. 50/50 is 100 mm. 40/40 is 80 mm, which DIDA also writes as 35:10:35. A 30/35, the Wavanta size, is 65 mm and will not pass as about 35. If the old cylinder already stands proud, pencil the handle face so you do not copy a barrel that was too long. West Yorkshire Police and the Master Locksmiths Association set the fitted limit at no more than 3 mm. Standfast Security’s 5 mm note is a measuring tip, not the limit to fit to. A thumbturn is handed. The T side goes inside. Which doors should have a turn is the thumbturn euro cylinder page.
greenteQ greenteQ Orion 35/35 thumbturn

Testsieger

greenteQ greenteQ Orion 35/35 thumbturn
8.6/10about £32.06
View offer

The screw, the 3 mm line, and a test with the door open

Offer the new cylinder with the cam at the bottom and slide it in until the screw hole lines up. A short screw is the failure greenteQ reviewers describe on thick doors. If the new screw is short and the old one is the right length, use the old one. If neither reaches, do not leave the cylinder held by the handles alone. With the door still open, throw the lock and release it. On a thumbturn, try the outside key with the turn left where you will actually leave it. One greenteQ reviewer found the outside key would not lock unless the turn sat in a particular place. Then look at the outside: no more than 3 mm of protrusion. The star wording is on the anti-snap euro cylinder page.

When you stop and call a locksmith

Stop if someone is locked in, if the key has snapped flush, or if the hooks still do not throw after the screw is tight. That last fault is often the gearbox. Keyed alike across Kitemarked cylinders is a registered locksmith’s job. An HMO bedroom, a fire door, or a new-build doorset is specification work. A Yale night latch uses a rim tail cut to the old length. There is no euro cam. If you are holding a rim cylinder against a uPVC door, change the product.

Common questions

Which screw comes out of a euro cylinder?
The single fixing screw on the edge of the door, level with the cylinder. Handle screws stay in. If you cannot see that edge screw, you may be looking at a night latch rather than a euro lock. A rim cylinder is held differently, and cutting its tail is not this step.
Why will the old cylinder not slide out?
The cam is still turned across the slot. Put the key in and turn it a small amount, often around 25 degrees, until the cam lines up and the barrel slides. If the key is snapped flush, or the cam will not move, stop. Forcing it is how the gearbox gets damaged.
Do I measure in the door or on the bench?
On the bench, once the cylinder is out. Measure from the centre of the screw hole to each end, not the overall length alone. If the old one already stood proud, pencil the handle face and order to that mark. Copying a proud cylinder repeats the projection you are trying to lose.
How far may a euro cylinder stick out?
No more than 3 mm beyond the door or the door furniture. That is the figure in West Yorkshire Police door advice and in the Master Locksmiths Association guideline of January 2025. A retailer tip of 5 mm is not the limit to fit to. A flush cheap cylinder beats a long expensive one.
The new screw is too short. What did reviewers do?
They reused the old screw when it was long enough and the thread was sound. greenteQ reviews mention short screws on thick doors. If the old screw is also short, do not leave the cylinder loose behind the handles. Get a screw that reaches, or return the cylinder.
Does this method fit a Yale night latch?
No. A night latch uses a rim cylinder. Yale’s listing covers doors about 38–57 mm thick, and the tail bar is cut to length. Cut it too short and the mechanism will not turn. The euro steps on this page, one edge screw and a cam, do not apply to that latch.

Related pages

Door lock

Lock cylinder

Best lock cylinder: street door, swap or night latch

Euro cylinder lock: match the profile and the split

Thumbturn euro cylinder: when the inside should turn

Anti-snap euro cylinder: what TS007 actually means

Sources

Public UK sources for the security rules, plus the amazon.co.uk listings in this set. Last checked 21 October 2026.

  1. West Yorkshire Police, euro-cylinder advice (retrieved 21 October 2026)
  2. West Yorkshire Police, door and window advice (retrieved 21 October 2026)
  3. Door & Hardware Federation, TS 007 (retrieved 21 October 2026)
  4. Master Locksmiths Association, domestic security guidelines, January 2025 (retrieved 21 October 2026)
  5. GOV.UK, Approved Document Q (retrieved 21 October 2026)
  6. Sold Secure, domestic security booklet (retrieved 21 October 2026)
  7. Lock and Key, how to measure a euro cylinder (retrieved 21 October 2026)
  8. DASH, locks on doors in HMOs, 2023 (retrieved 21 October 2026)