Most front doors and many back doors in Aspe, from flats in Huerta Mayor to new villas in Santa Elena, use a euro cylinder: the barrel the key goes into, held in the lock by a single long screw on the edge of the door. Cylinders come in many lengths, and the right one sits almost flush with the door or its plate. Too long, and it sticks out where it can be gripped and snapped; too short, and it will not reach the lock properly.
Measuring it yourself means the right cylinder can be brought on the first visit.
What you need
A ruler or tape measure in millimetres, and the door open.
The two measurements
- Find the fixing screw on the edge of the door, in line with the cylinder, usually below the latch. Its centre is the reference point.
- Measure from the centre of that screw to the outside face of the cylinder. That is the outside measurement.
- Measure from the centre of the screw to the inside face of the cylinder. That is the inside measurement.
Write them as outside / inside, for example 30/40. The two numbers are often different; that is normal.
Common mistakes
- Measuring to the face of the door instead of the cylinder. Measure the cylinder itself, then, separately, note how far it sticks out beyond the door or plate.
- Measuring from the edge of the door. Always from the centre of the fixing screw.
- Forgetting a thumb-turn. If the inside has a knob instead of a keyhole, say so: it is a different cylinder.
Do not take it out yourself
You can unscrew a cylinder, but it only comes out with the key turned to exactly the right angle, and a cylinder half out of a door that will not lock is not where you want to be at night.
Two photos — one of the edge of the door, one of the cylinder from outside — help as much as the numbers. If the door is an older one with a long key rather than a cylinder, read is the lock as old as the door?, and if you are replacing it because of marks round the keyway, see signs someone has tried your lock.