Ward

A ward is a fixed obstacle inside a lock, a metal tab or ridge, that only lets a key turn if its bit has the matching cut. On old locks with large keys it was the main security system.

You can recognise it on the key itself: the cuts and notches in the bit that do not lift any part, but are there to pass the wards without catching.

Warded locks are easy to open with a cut-away key that dodges the obstacles, so today they offer very little protection. You will find them on farmyard gates, old storerooms or antique furniture. If you still have one on a door that opens onto the street, replace it with a cylinder lock. More under lock installation.