Cylinders & keys
How do you measure a euro-profile cylinder?
To replace a euro-profile cylinder, two lengths must be measured, not just one total length. The door handle and cylinder guard must also be considered to achieve an appropriate fit.
KEY POINTS
The reference point is the centre of the cylinder screw fixation. Clearly note which dimension corresponds to the outside and which to the inside.
Understand dimensions A and B
Both measurements start from the centre of fixation and extend to each end of the cylinder. A mounting can be symmetrical or asymmetrical. Two cylinders of the same total length can therefore have different distributions.
For example, a 30/40 distribution does not correspond to the same mounting as a 35/35 distribution. The order of the dimensions and the side of the button, if any, must be specified at ordering.
Take into account the door furniture
The measurement must match the door thickness including handles, ornamental plates and protective elements. The cylinder must not extend excessively on the outside, but the key entry must remain usable with the selected door furniture.
If you are also replacing the handle with a secured model, take the new dimensions into account. Ordering the same cylinder as the original without verifying this change may result in an incorrect length.
Measure and dismantle under good conditions
Work the door open. If you know how to remove the cylinder according to the installation, a measurement of the removed part allows confirmation of dimensions. Do not force if the cylinder is retained by a door furniture or a specific mechanism.
Measurements taken on the door can help identify the cylinder, but the fixing screw must be located accurately. Side-on photographs of the door edge and both sets of door furniture help the locksmith check these measurements.
Check the other features
Length alone is insufficient: profile, cam, drive mechanism, button, and disengageable function must match. For a half-cylinder or a specific lock, use the dimensions and specifications from the relevant reference.
After replacement, test several open and close cycles without forcing. On a certified lock, also verify that the retained cylinder is part of a compatible configuration.
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