Mortice locks are used for most internal doors, they are available with or without keys and come in different shapes and sizes.

 

Recommended Tools

Drill • Chisel • Screwdriver • Bradawl • Pencil

	Determine the height that you want the lock to be, then place the lock on the side of the door draw round its body and mark the spindle hole and any key hole. Using a try square draw lines across the edge of the door in line with the marks for the top and bottom of the lock body.
	Measure the thickness of the door and half it, then draw a vertical line where the lock is going to go. Place the back of the lock on this centre line and draw round it, this is the bit that will need to be removed to fit the lock. Drill a row of holes, the same width as the lock. Measure to make sure the holes are deep enough.
	Use a chisel to straighten the sides and remove the bits left in between the holes. Clean out all the splinters and try the lock to see if it fits. Chisel out as required until the lock fits, then with the lock pushed fully in draw around the face plate. Chisel a recess for the face plate to the required depth.
	Drill out the spindle hole and the key hole if it has one, using appropriate size drill bits. Fit the spindle to test the lock and also test the key if fitted.
	Once you are happy that everything lines up and works freely, use a bradawl to make small pilot holes for the screws then screw the face plate in place and fit the handles.
	To find the position of the striker plate, partly close the door and mark the top and bottom position of the door catch on the frame, now fully close the door and measure the distance from the catch to the edge of the frame. Using the marks and measurement line up the striker plate and draw round the outer and inner edges, using a chisel cut the recess to the depth of the striker plate, then cut the centre hole to the depth of the catch and screw the striker plate in place.