Deadbolt, deadlock, deadlatch: three words that get used for the same thing, even though they aren't. Here's what each one is, how to tell which you've got, and when it's worth changing.
Deadbolt
A deadbolt is a separate bolt, usually above the door handle, that you throw with a key from outside and a key or thumb-turn from inside. It has no spring, so it can't be pushed back with a card or a knife once it's locked. On a timber door it's normally a round lock fitted through a drilled hole.
Deadlock
In New Zealand "deadlock" is the everyday word for the same idea: a lock that can't be forced back once it's locked. Most people call a deadbolt a deadlock, and many mortice locks, the ones set inside the edge of aluminium and commercial doors, are deadlocks too.
Deadlatch
A deadlatch is different. It's a spring latch that locks itself when the door shuts, like the classic front-door nightlatch, with a small plunger that stops the latch being slipped. Many can also be deadlocked with the key. Handy, but a latch on its own isn't as strong as a proper bolt.
How to tell what's on your door
- Does it lock itself when the door closes? Then it's a latch or deadlatch.
- Is there a separate lock above the handle that you turn with a key or thumb-turn? That's a deadbolt.
- Is the lock body buried in the edge of the door, with a key cylinder in the handle plate? That's a mortice lock, and it's usually a deadlock.
Still not sure? Text a photo of both sides of the door and its edge to 022 513 3957 and we'll tell you.
Which is most secure?
A good deadbolt or mortice deadlock, fitted properly, beats a latch on its own. The fitting matters as much as the lock: the bolt has to throw fully into a strike plate that's firmly fixed into the frame. A misaligned strike is the most common fault we find on deadbolts people have fitted themselves.
When to upgrade
- Your front or back door only has a spring latch.
- The deadbolt is stiff, only half-throws, or the key has to be jiggled.
- There's glass within arm's reach of a thumb-turn. A double-cylinder deadbolt fixes that, but keep a key near the door so you can get out quickly.
- You've just moved in. Rekey the lot so old keys stop working.
We fit and replace deadbolts across the North Shore and key them to match your other locks. See deadbolt installation or call 09 972 4640.