Euro cylinders are measured in two halves, separated by the central fixing screw. Take both measurements from your existing cylinder before ordering, and match them to the size listed above.
A — Internal side
Measure from the centre of the fixing screw to the outer edge of the cylinder on the side that faces inside your home. Common sizes are 30mm, 35mm, 40mm, 45mm, or 50mm.
B — External side
Measure from the centre of the fixing screw to the outer edge of the cylinder on the side that faces outside your home. Common sizes are 30mm, 35mm, 40mm, or 45mm.
Cylinders are typically described as A/B — for example, a 35/45 cylinder has 35mm on the internal side and 45mm on the external side. Get both measurements right and the cylinder will fit your door perfectly.
Still unsure? Send a photo of your existing cylinder to info@homesecureshop.co.uk and we'll match it for you — or call 0151 521 8089 to speak to our team.
Measured up?
We stock euro cylinders in every common size from 30/30 up to 50/50, from standard cylinders through to ABS 3-star anti-snap — the highest kitemark security rating available. Need several locks to work with one key? Look for our keyed-alike options. And if the size you measured isn't listed, call us on 0151 521 8089 — we can usually get it.