I’ve been thinking about exterior door locks recently. I moved into this house five years ago, but never changed the locks. For someone supposedly security conscious, this is a terrible practice. It wasn’t until I started looking into the problems with common exterior door locks, which are typically euro locks in my part of the world, that I began to understand the risks were from more than just prior keyholders.
Typical euro cylinder locks as found in a large proportion of exterior doors here are vulnerable to a whole variety of attacks. The most common and prevalent with respect to burglaries is “snapping”.
The design of euro cylinder locks leads to a vulnerability where an attacker can literally “snap” the cylinder in half by applying lateral pressure to the exposed portion on the exterior side of the door. This results in the cylinder snapping in the middle, allowing full access to the inside of the mechanism and simple entry from there.
Double euro cylinders are available for purchase that aren’t vulnerable to snapping attacks. This variety still snap, but an intentional weakness in the front half of the cylinder creates a “sacrifice” section. When the lock is forced from the exterior, this sacrificial portion snaps, with the internal mechanism still inaccessible, leaving nothing exposed on the exterior to apply force against. The lock still operates from the interior side.
Upon examining my own exterior door lock cylinder for the first time, I found it has no sacrificial snap portion. I have purchased a new double euro cylinder with snap protection and other common attack defences and look forward to fitting it when it arrives.