Lock Snapping: Why Your uPVC Door May Be Vulnerable

Published 11 June 2026

Lock snapping accounts for a large share of burglaries through uPVC and composite doors. The attack is brutal and simple: grip the protruding cylinder, snap it at its weak point, and the door opens in well under a minute with no skill required.

Is your door vulnerable?

• Your door uses a euro cylinder (the pill-shaped lock most uPVC doors have).
• The cylinder protrudes more than a couple of millimetres past the handle plate.
• The cylinder has no kitemark and no star rating stamped on it.

The fix: rated anti-snap cylinders

Look for TS007 3-star (kitemark with three stars) or Sold Secure SS312 Diamond cylinders. They are engineered with sacrificial sections so the front snaps off harmlessly while the locking mechanism stays intact. A 1-star cylinder paired with 2-star security handles also meets the standard.

Fitting is quick — usually well under an hour for an experienced locksmith — and it is the single best-value security upgrade for most modern homes. While the locksmith is there, ask them to check the cylinder is the correct length for your door, since an overhanging cylinder undermines even a rated lock.