Interior Mortise Lock Sets
(previous woodworking experience recommended )

Unwrap all components, laying them within easy reach. You will need a drill (with 5/8”, 9/16”, 3/4”, 3/8”, and 3/32” bits), wood chisel, medium phillips screwdriver, ruler, and nail polish or threadlock.

Reversing Lock Handing:
(If lock is already facing correctly, skip this step) It is important to determine if your lock is facing the correct way before installation. PLEASE SEE BACK SIDE FOR INSTRUCTIONS ON REVERSING THE HANDING OF A MORTISE LOCK.

Door Preparation:
(If door is already mortised, skip this step) Choose a location for the lock to install, centered approx. 36”-38” from the floor, or in a pleasing location. Place the enclosed template on the edge of the door with the arrows in line with the center line. Mark the position of the screw holes and the centers of the holes to be drilled for the mortise, keyhole, and knob spindle hole. The 2 1/4” dimension between the spindle and the keyhole is critical.
Drill out the holes for the mortise cavity with a 5/8” bit to a depth of approx. 3 1/4”. Chisel out the remaining wood to form the lock cavity. Use a 3/4” bit for the spindle hole and a 3/8” bit for the keyhole. Center the lock in the lock cavity and use a sharp awl or razor knife to scribe a line around the faceplate.
Remove the lock and use a chisel to cut an approx. 1/8” deep mortise, so that the lock face will lie flush with the door edge. Install lock into the door. Tighten screws securely. Use your key to check lock function before proceeding.


Gently back the set screws out of one doorknob approx. 1/2 way, or until they do not protrude through the spindle hole. Remove the doorknob. You should now have one doorknob still on the spindle and one loose doorknob. Holding the knob which is on the spindle, slip the spindle through one of the door plates and guide the spindle through the square hole in the mortise lock. Slide the other door plate onto the protruding spindle and screw the remaining knob onto the spindle, snugly to hold plates in place.
Use a ruler to make sure that the plates are parallel to the edge of the door. Give the knobs a bit of a wiggle to align them and keep them from binding against the plates. Screw the top screw(s) into one door plate, then the bottom screw(s), and again check your alignment. Follow with the plate on the other side. Now, unscrew the doorknobs about 1/2 turn or just until they turn freely. If all is still aligned and the knobs turn easily, screw in any remaining wood screws.

Loosen set screws and remove both doorknobs from the spindle. Center the spindle in door latch. Slide the round backplates over the spindle on each side of the door. Center each plate over the protruding spindle and screw in wood screws. Screw doorknobs onto the spindle, allowing enough slack so that they turn freely. Center each keyhole over keyhole opening in door and install wood screws.

Finishing the Knob Installation:
Screw in all set screws carefully, making sure that they tighten against the flat part of the spindle (a slight wiggle can help to set them in place). Try the doorset, making sure that everything works smoothly. If there is binding, try loosening the screws on the face of the lock slightly. Lastly, remove each set screw, one at a time, and coat threads with fingernail polish or threadlock. Replace each.

Installing the Strike:
Placing the strike in the correct position is very important for proper doorset function. Dirty the angled edge of the latch tongue with a soft pencil and close the door so that the latch rubs a pencil mark onto the door jamb. Repeat until a black smear is clearly visible, showing the path of the latch tongue. Center the strike over the black mark. Mortise for strike similarly to the procedure used for the lock face. Use a 9/16” drill bit to cut the hole for the latch tongue and lock bolt. Install strike.