Another very important consideration is the strength of the spring in the latch. Most lever handle comes with a sprung return, if the spring in the latch is to strong there could be an issue when operated by the very young or very old due to the pressure needed to trip the catch. On the flip side most mortice knobs do not come with an internal spring, so if the spring in the latch is weak then the catch will not return properly when operated.
Tools required for the job are as follows.
Small Pilot Drill Bit
20mm Forstner Drill Bit
10mm Forstener Drill Bit.
Once you have decided on the correct position of the handle mark a line on the door edge and using the setsquare transfer these lines to either side of the door. Mark the centerline on the door edge, then measure the distance from the edge of the latch plate then transfer this measurement onto each side of the door.
With the door held securely drill a hole into the edge of the door using the 20mm forstener brill bit, make sure you drill deep enough to accommodate the latch.
Using the 10mm forstener drill bit drill the two clearance holes on either side of the door, remember to drill from both sides to avoid breakout.
Offer the latch up to the door, then making sure it is square mark the two fixing holes with a pencil and drill two pilot holes. Using the countersunk bit remove excess material to allow the latch to fit flush against the door in readiness for marking out.
Offer the latch back up to the door and fix in place with both screws, then using a craft knife carefully cut around the latch plate and remove.
Using a sharp chisel remove enough material so that the latch plate will fit flush to the door. Again using the countersunk drill countersink both holes to allow the reverse of the plate to fit snugly into the opening. You can now permanently fit the latch.
Partially close the door and mark out where the catch part hits the door surround. Open the door and offer up the striker plate to the correct position and mark the two fixing holes with a pencil.
Pilot drill the two pencil marks then screw the striker plate back into place. Then using a sharp craft knife mark around the striker plate and remove.
With a sharp chisel remove enough material for the striker plate to fit flush to the doorframe, countersink both holes and fit the plate for the final time.
Finally using a narrow chisel removes enough stock material from within the striker plate to allow the catch fully open once the door has been closed.
Thank you for watching our video blog I hope you found it of some use. Next time we will be discussing how to fit an un-sprung beehive mortice doorknob.
Update: You will notice that the knob was positioned on the upper part of the rail. Ideally it should be dead centre of the rail.