Keyhole Router Bit

Keyhole Router Bit

How To Fit A Mortise Lock

Always position a mortise lock in the centre of the door edge where it will give the strongest fastening. There is a specially reinforced point for fixing on some doors. This will be marked on the door edge.

First wedge the door open so that it can be worked on from both sides. Some manufactures provide a cardboard pattern for marking out the lock position on the door. Other wise use the lock body as a template to mark out the mortise. Place the pattern or casing against the side of the door and mark around is outer edge in pencil. Remember that the faceplate is recessed into the outer door edge so if you are using the lock itself the mortise will in fact be approximately 4mm deeper than you have marked it.

Continue the line onto the edge and other side of the door using a square or lock casing body again. Then set a marketing gauge to half the width of the door and score a vertical line down the outer edge between the two marked out lines. If you do not have a gauge, measure this distance with a rule.

The mortise should now be drilled and cut. When you have finished, try the lock body in position and make sure that the cover plate is level with the door edge. Mark around the outside of the cover plate and remove the lock.

We used our Stanley chisel to cut out a rebate so that the plate fits flush against the door edge. If your feeling clever you could use a small router for this, however I know many people who have gone straight through the side of the door doing this. Trend Machinery sell a excellent lock jig that solves this problem. If you are going to fit fitting a larger number of locks the trend lock jig is defiantly work a look.

Now mark and cut the key holes. Hold the lock body against each side of the door in turn and push the point of the bradawl through the keyhole cut in the lock casing. This will mark the door with the exact position of each keyhole.

Remove the lock and with 13mm drill bit bore two holes through to the centre from either side of the door. We used the Panasonic 7440 for this. The keyhole shape can then be cut out by using a pad saw or with a small chisel, (we did not have a pad saw to hand at the time of writing so we used one of our Stanley chisels again). You can cut a bigger hole that what is needed as in most cases the keyhole will be covered by a face place. Once the key hole has been cut, slide the lock into position and try the key from both sides. If every thing is ok you and then screw the lock into the door.

All that remains is to fit the striking place into the doorframe. This is usually the making or breaking of most locks. So take your time and remember measure twice cut once.

To mark the position of the rebate hold the door open and turn the lock. Remove the wedge, and then push the protruding bolt against the frame and mark top and bottom with a pencil. This will tell you how deep to cut the rebate but not the exact position in which it has to be cut. Instead of relying on guesswork, it is possible to get a more accurate result by marking the bolt end with chalk or crayon then stuffing the door and turning the lock a number of times. The result will be a chalk mark where the end of the bolt strikes the inside of the doorframe.

With a 12mm, chisel chop out a square sided hole to accommodate the bolt. The hole should be a few millimetres wider and deeper than marked to allow for a slightly larger bolt box.

One the bolt box is cut, slide the plate into position and mark around the outside with a pencil. As with the lock body, you will find in easier to cut a rebate if you run a trimming knife around the outside of the striking plate first. Chisel out the rebate then mark and pre-drill the screw holes with the bradawl. Before securing the plate, make sure that the door will close properly.

About the Author

Johan Nickson has been an expert in the DIY industry for Thirty Years and has always been a huge fan of
Panasonic Drills

CNC cutting keyhole slots