I have a metal building with a metal entrance door. It already has a door knob lock, however I would like to install a deadbolt. I know how to install a deadbolt on a wooden door, but never installed one on a metal door. The lock I purchased has the rectangle plate on the bolt so if you installed in a wooden door, you would mortise the door so you can have a flush installation. But on a metal door you cannot mortise it. So what do you do for a metal door? Is there a special deadbolt you install without having to mortising the door or do you just install the bolt without mortising? Also I have almost no room between the door and the frame therefore just trying to install the bolt without mortising would cause the bolt plate to hit the door frame.