For a euro-profile cylinder, record the two sides separately rather than ordering by total length alone. This guide concerns measurement and purchasing coordination on a door you are authorised to maintain. It is not a lock-removal or bypass guide; use a qualified installer when the configuration is uncertain.
Establish the Measurement Reference
ABUS describes measuring from the centre of the fixing screw in both directions, accounting for the fittings. Identify the exterior and interior explicitly on your record. Do not assume that suppliers use A and B for the same sides: include a labelled sketch or photograph.
A total length can conceal a different split. For example, 30/40 and 35/35 both total 70 mm, but describe different side lengths. These are arithmetic examples, not a recommendation or a statement of available WONLY sizes.
Record More Than Two Numbers
- Door mark, quantity and location.
- Exterior-side length and interior-side length, in millimetres.
- Handle, escutcheon or protective fitting details and any proposed changes.
- Key/key, thumbturn or other required operation.
- Existing lock-body identification and cylinder profile.
- Required key-management arrangement and evidence to be reviewed.
If fittings are changing, survey the proposed finished arrangement rather than copying only the old cylinder. Ask the supplier to confirm the correct body length and the permitted relationship to the protective fitting. There is no universal projection allowance suitable for every product.
Treat Length and Compatibility as Different Checks
Correct dimensions alone do not confirm that a cylinder will operate the lock. Have the installer and supplier verify profile, drive or cam arrangement, fixing and operating requirements. A smart retrofit or specialist lock may impose additional conditions. Do not infer those conditions from a photograph or an overall length.
The same caution applies to performance claims: dimensional fit does not establish a security rating or preserve a complete doorset's approved configuration.
Use a Written Approval Record
Send the inside/outside sketch, measurements, fitting details and lock identification without exposing key codes or customer access information. Ask for written confirmation of the proposed part and unresolved questions before buying in quantity. Test an approved sample through the authorised installation process before rollout.
FAQ
Can I order by door thickness? Not reliably; the finished fittings and cylinder arrangement also matter.
Can I swap the two side lengths? Do not assume so. Confirm which side is external and whether the design has directional features.
Does a matching size guarantee suitability? No. Size, operation, compatibility and evidence are separate checks.
Source and Next Step
The measurement reference is based on ABUS's cylinder measuring guidance. The cover is an illustrative image, not a dimensioned product drawing. Send the recorded specification to WONLY for a configuration review; model availability must be confirmed.
