The distance between the edge of the door and the center of the lock hole.
Fitting front door lock.
Usually the backset measures 2 3 8 inches or 2 3 4 inches.
Take care with the marking out and drilling to ensure excellent results.
A 5 lever mortice deadlock conforming to bs3621 will have the british standard kitemark engraved on the faceplate of the lock and operates the same way as a standard 5 lever mortice deadlock.
The key to success is getting the hole for the cylinder in the right position.
5 lever mortice deadlock conforming to bs3621 more secure type of front door lock back door lock.
Interior doors are usually fitted with a mortise lock with a latch operated by the door handle or knob.
Before purchasing a lock measure your door s backset cross bore and thickness to ensure you find the right fit.
For front doors it is best to fit two locks a mortice deadlock about halfway up and a night latch one third of the way down the door.
Fitting a front door rim lock fitting a rim lock the yale type lock on your front door is fairly straight forward.
If you don t get this precise the lock may not fit properly.