They usually come with fitting instructions including a cutting
template in the pack. Use the template to mark up the door, remove
most of the wood for the case of the lock by drilling a single line of
large holes and then using a chisel to remove the remaining waste wood
to form a rectangular opening. Chisel out the rectangular recess for
the faceplate, and drill the holes for the handle and thumb turn.
Drills and chisels.
Mark out the 4 corners which need to be cut out. Drill down each of
these corners. A 10mm drill is good for this.
Then get out a 16mm (19mm may be ok, depending on your lock width)
forstner bit, and drill out as much as possible of the remaining wood
between the corners. Be sure your drill goes in straight, otherwise it
will come out of the side - ruining the door in many cases.There is only
around a 6-8mm gap between the door edge and cut out, so be careful all
the way down.
Once you've drilled out all you can, get a decent chisel, and start
cleaning the cut-out out, to give a nice flush fit for the lock.
Once it is sliding in well, you need to cut out the opening for the
outer section of the lock. This is fiddly, as the edges are within 3mm
of the door edge, so easy to take a chink of the wood out.
Now it should be a good, tight, but easy to get in, fit. Take it out,
and mark up the holes for the lock key and handle spindles.Drill through
with a 16mm drill/forstner bit.Do one side at a time, then turn the door
over, if you drill straight through, you are likely to splinter the rear
door face around the hole. To get both holes in line, run a small pilot
drill all the way through - 2mm will be fine if you've got a long enough
And thats about it for a lock.
I charge £40 to fit a new mortice locked door from scratch - too cheap I
think, considering the skill needed to get them right every time.
That's the same as the one I used ( but in brass) along with a tubular
mortice similar to this .
the cutting out you need is for the mortice latch .Turning the
thumb thingy at the bottom locks the handle .Easy peasy and for
safety the lock can be released from the outside by use of a coin or
screwdriver in the slot on the other side .
To save my poor fingers in writing a description, the following link will
give you some idea on how to go about it.
answers you're original question, but unless you want security as well
as privacy, there is an easier way to go about 'locking the door' - a simple
3" (75mm) brass barrel bolt screwed to the inside of it.
As your link shows - it will be easier to use an auger or flat bit of the
correct size (around 20mm).
There is only a need to drill a single hole in the edge of the door for the
catch -- and a single hole through the face of the door using the same bit
for the handle spindle - no cleaning up with a chisel needed here then.
The only chisel cutting needed will be to cut the elongated slot for the
latch 'holding' and receiver plates.
Nice link by the way - brings back a few memories looking at the 3" x 2"
timbers hold the door on edge. Used these dozens of times when I was too
idle to carry - or even make - the old saw horse.
Remember the OP was asking about a bigger mortice lock though, and not a
simple tube latch as shown in the piccies. Hence my comment at the
bottom of the wiki article that you will need to drill several partially
overlapping holes with your auger or spade bit to clear the space for
If you are using the type of lock the OP cited :
you will need to remove a slot of timber in the door as well to
accommodate it. Unless you can find a way to space the holes very close
to each other with substantial overlap, I would be surprised if you
could do it all without a chisel.
Yup, handy for doors as they leave it at the right working height... the
other alternative I find is to clamp the end in the edge of a workmate,
but its not as stable.