How to Replace a Mortise Lock With a Tube Lock

Prepare the Door

• 1

  Locate the set screw under the lip of the knob on the inside face of the door. Turn it counterclockwise to release it and pull the knob from the spindle. Grasp the knob on the outside face of the door and pull it and the spindle from the door.

• 2

  Remove the screws in each corner of the face plates on both faces of the door and lift them from the door. Remove the screws holding the lock in place from the edge of the door and pry the lock from the door with a small screwdriver.

• 3

  Measure the mortise hole in the edge of the door from front to back and side to side. Insert the end of the tape measure inside the mortise to measure its depth. Cut a block of pine to match the hole's dimensions using a table saw.

• 4

  Insert the wooden block into the door. It should fit smoothly. Use a wood rasp to shave the block down to fit smoothly, if necessary. Apply wood glue to every face that will be inside the door and reinsert the block. Drive two 1-inch finish nails through the face of the door into the block.

• 5

  Fill any gaps in the edge of the door and the holes in the face of the door with wood filler. Allow the filler to dry and sand the door smooth with 120-grit sandpaper.

Installing the New Lock

• 6

  Apply the paper template that comes with the new tube lock to the door's edge at a height centered on the striker plate hole in the door jamb. Mark the center of the hole on the face of the door with a hammer and awl. Mark the center of the striker bolt hole on the edge of the door.

• 7

  Bore a 2-1/8-inch hole through the door centered on the door face using a hole saw. Do not force the saw through the back of the door because this will cause splintering. Allow the saw to cut through smoothly at a steady pace. Bore a 1-inch hole from the mark on the door's edge into the round lock mortise hole you just bored.

• 8

  Center the striker bolt collar plate on the hole in the door's edge and trace around it. Use a wood chisel to cut the material inside the outline to a depth of 1/8th of an inch. Insert the striker bolt through the hole in the door's edge and attach it using the screws provided with the new entry lock set. Drive the screws into the door's edge with a drill.

• 9

  Insert the two halves of the tube lock knob combo through the holes in the striker bolt. Make sure the key hole is on the outside of the door. Align the two halves of the knob and thread the screws through the knob. Tighten the screws with a screwdriver.