How to Make Your Own Simplex Lock

Mark the door for placement of the appropriate holes for the model of Simplex lock you are installing. The lock kit should include a paper template for ease of placement. Drill the holes that are marked. They should range from a quarter-inch to more than 2 inches in diameter.

Mount the latch unit, or bolt, and its faceplate. Mortise or chip away part of the door if needed ensure the plate is flush with the edge of the door.

Measure the width of the door. The Simplex lock is usually pre-set for doors approximately 1.625 to 2 inches wide. If the door is narrower, remove the cylindrical drive unit and remove the enclosed spacer. If the door is wider, remove the drive unit and add a spacer. Reattach the cylindrical drive.

Place the outside unit assembly, which includes the keypad, onto the outer side of the door until it is flush with the door face. The cylindrical drive unit should slide into the largest hole you made in the door. Make sure the drive unit and latch click together

Place the inside unit assembly against the inner face of the door, so the drive hub slides into the largest hole on this side, and meshes with the sleeve of the cylindrical drive unit.

Attach the inner unit to the door using four screws. Their lengths are based on the width of the door, as they range from 2.5 to 3.75 inches.

Install the doorknobs or door handles by attaching one to the inside unit assembly and one to the outside unit assembly. If your model of Simplex lock takes a key, test it to ensure the key cylinder is secure and the key turns the knob. Test the combination to the keypad to ensure it also opens the lock and allows you to turn the knob.