What does backset size mean?

The backset is the distance from the edge of the door to the center of the 2-1/8-inch bore hole. In the United States, there are two common backsets for residential door locks: 2 3/8 inches and 2 3/4 inches.

What does backset mean on door lock?

The backset is the distance from the edge of the door to the spindle mechanism on the latch. Usually for a 63mm case measurement it will have a 44mm backset and for a 76mm case measurement will have a 65mm backset.

What is the backset of a lock?

The backset is the horizontal distance from the edge of a door to the centre of a lockset; thus, the distance a lockset is ‘set back’ from the edge of a door is called its backset. It’s usually 1 inches or 2 inches (or 44mm and 57mm).

Which is the correct size for a door lock backset?

The backset is an important measurement as it specifies the distance from the face of the lock to the centre of the keyhole. This allows you to correctly line up with existing holes in the door rather than drilling new ones. The most common sizes here are 44mm and 56mm (give or take a few millimetres).

How to measure a backet for a lock?

The way to measure for your back set is you grab your tape measure go to the edge of the door and pull it across. Here we have this bottom hole drilled out for two and three quarters. You either measure at the center of the key hole or at the center of the lock on top I like to measure on top,…

What do you mean by backset on a door?

‘Backset’ is the distance from the front of the lock to the centre of the spindle as shown here. If you intend to use new locks or latches on an old door, replacing your old ones, you will need to make sure the new one fits into the hole in the door. To do this, measure the ‘backset’ distance of your old lock. Check the other dimensions too …

How big is the backset on a mortice lock?

Almost ALL domestic mortice locks and tubular latches are supplied with either a 44mm or 57mm backset length. These equate to case sizes of 2.1/2″ or 3″ in imperial measurements. Commercial (DIN) lockcases are 60mm backset. If you are not sure what you need, then drop us an email with a photo, or phone in to chat it through.