Cylinders and Barrels for Smart Locks

The mechanical override cylinder inside a smart lock, and the replacement barrels for it. Worth attention, because a strong electronic lock fitted with a basic cylinder is only as secure as that cylinder. This is also where keying alike to an existing system is done.

Getting the right cylinder

Check	Detail
Profile	Euro profile, oval or proprietary. The lock case determines which will fit
Length	Measured either side of the fixing screw centre, for example 30/30 or 35/45. Must match door thickness and escutcheon depth
Configuration	Double cylinder, single with blank, or key and thumbturn
Cam type	The driving cam must match the lock case. Standard and proprietary cams are not interchangeable
Keyway	Standard or restricted. Restricted controls who can cut a copy
Finish	Only relevant where the cylinder face is visible once fitted

A cylinder that protrudes more than a few millimetres past the escutcheon face can be gripped and snapped. Measure the door and escutcheon depth and specify the length accordingly rather than fitting the nearest available size.

Keying alike

Where the smart lock override should open with the same key as your existing doors, the cylinder can often be re-pinned to match, provided the keyway is compatible. Bring in a key and the existing cylinder to confirm. Restricted systems require authorisation to add cylinders.

Related categories

Smart Locks With Backup Key · Keys and Key Blanks · Mortice Locks · All Accessories

Common questions

How do I measure cylinder length?
Measure from the centre of the fixing screw hole to each end face. A cylinder described as 30/45 is 30 mm on one side of centre and 45 mm on the other, giving 75 mm overall.

Can I upgrade to a higher security cylinder?
Usually yes, provided the profile and cam match the lock case. This is a worthwhile upgrade on any smart lock whose override cylinder is a basic unit.

Guides and reference

Mechanical key override explained · Ch 01 - The mechanical layer