Door Lock Backset Measurement
Pack your locks with a 2 3 8 inch or 2 3 4 inch latch depending on which backset you specify.
Door lock backset measurement. Backsetthe distance from the edge of the door to the center of the lock bore. These smaller backset sizes are generally european and some are still in use today. Sometimes it s easier to measure from the edge of the door to the highest point on the bore hole. Some older residences will have variations to installed locks.
Mortised latches come in a radius corner rounded on the edges or a squared corner configuration. If you dont have any hardware on your door just measure from the edge of the door to the center of the bore hole the large hole where the door knob assembly is mounted. The backset measurement is the distance from the centre of the keyhole to the leading edge of the lock. Check the other dimensions too most of our pages show plate and lock case dimensions.
In the uk and much of europe these dimensions can vary from 25 to 60 mm and many medallion knobs are placed in the center of the door creating a very large backset. In the united states there are two common backsets for residential door locks. Most commercial doors have a backset of 2 3 4 inches 69 8 mm while residential doors measure 2 3 8 inches 60 3 mm. These equate to case sizes of 2 1 2 or 3 in imperial measurements.
To do this measure the backset distance of your old lock. The backset is the distance from the edge of the door to the center of the 2 1 8 inch bore hole. Falcon used to make a 5 backset that would work with emtek hardware but i believe it is no longer available. There is a range of backset long body locks at 20mm 25mm 30mm 35mm 40mm 50mm and 70mm.
2 3 8 inches and 2 3 4 inches. Standard backsets are either a 2 3 8 backset or 2 3 4 backset. The backset is measured by placing a tape measure or ruler from the center of the keyhole to the forend of the mortice lock. The most common sizes here are 44mm on a 64mm 2 5 lock case and 56mm on a 76mm 3 lock case.
5 backsets are only available for some schlage locks and some kwikset locks. Other backsets include 2 used by national and lori lock and 5 used by weiser weslock kwikset and others. Two standard backsets are 2 3 8 and 2 3 4. This is very important when replacing locks because you don t want to have to drill new holes if you can help it.
Please see the demonstration below. Dead bolt latches top 2 3 4 bottom 2 3 8 note.