Deadbolt Installation in a Steel Door

Today I installed a new lock set in a steel door. The door edge was cut for a deadbolt, but no holes were drilled.
 
 
 
 
 
 
 
 
 
 
 
 
 
 

First, I marked the center of the cut-out on the edge of the door. Using a combination square, I made a mark 2 3/4″ from the edge mark on the face of the door. I center punched the mark and cut a 2 1/8″ hole through the door with a hole saw. I drilled a 1″ hole through the center of the door edge to intercept the 2 1/8″ hole.

Most steel doors have a wooden frame around the inside edge. Additionally, the core of this door is filled with foam. If the door was hollow, I would have inserted blocks of wood through the holes and locked them in place with expanding foam. This would provide structure to support the lock set.

A new lock set and a happy mother-in-law.