Locksmithing and Security

“Snib” is a more correct term for what is often known as the latch button on a latch lock.

A latch lock is the kind that can slam shut behind you, locking you out. Usually when you’ve decided to nip quickly out onto the doorstep in your dressing gown in order to get the milk delivery.

The snib is the little button that locks the latch bolt in the open position, and sometimes in the closed position as well. There are at least two reasons for checking that the snib isn’t loose.

Firstly if you have a dog (or cat?) that has the habit of jumping up and pawing at the locks, then Fido just might manage to activate a loose snib and lock you out.

This has now happened twice to one of my customers. They didn’t believe me the first time and wouldn’t let me change the lock. Now they are believers.

Secondly, if a snib has become loose and the lock is a “nightlatch” style lock on the “dangerous” side of the door (for a Yale 77, 84, 85, 88 or 89, for example, the “dangerous” side is the left as you look from the inside) then slamming the door could cause the snib to drop and lock you out — if down is the locking direction. (When mounted on the other side of the door a dropping snib is dropping towards the open and safe position.)

What is a dropped snib? Is it one of the many ailments that torment us over-fifties?

Snib or holdback are the correct terms for the part of a lock that stops a door latching behind you as you pop out to the dustbin in your dressing gown. It’s often incorrectly called the latch; latch, however, is what a door is doing if it locks as it closes, without your having to take any action other than close the door.

On locks that don’t have much sophistication, as well as holding the latchbolt open, the snib can also lock the latchbolt closed even against the correct key.

A dropped snib is when the snib gets loose, and when the lock is fitted to the unlucky side of the door, and when as you slam the door and it latches shut, the snib falls down and locks you out.

So, which way would your snib be going if it fell downwards? Would it be falling towards inactive? Nice green tick! Or falling towards active? Nasty red cross! If, for example, you had a Yale rimlatch lock on the right-hand side of your door (looking at the door from the outside), then I’m afraid it doesn’t fail safe, it fails the vexatious way.

If you have a simple latch lock and it’s on troublesome side of the door, keep an eye out for the snib getting loose and floppy.

If you like finding things to worry about, I have one more for you. Is there a big gap between the door and the frame? It has been known for a latch lock to be snibbed to the locked state while the door is actually open, and then for the door to slam shut. The gap is big enough that the bevelled latch bolt can enter the bolthole, but it can’t then be got out again.