>>/760/
>>/761/
Just a note: what I have done is very similar, I measured 6 inches above and below the doorknob. One deadbolt installed 6 inches above the doorknob and one deadbolt installed 6 inches below it. This creates bigger threshold for any intruder to have to bust open, making the door much more sturdy.
I then milled out a long strike plate using steal shelving beam metal for my door frame that fits both my deadbolts and doorknob locks. I used 3 inch screws to mount the strike plate to the door frame. I then got sheet metal and cut it to size to re-enforce the door itself (front and back) making cut-outs for mounting around the doorknob and deadbolts of-course.
Then I replaced the small screws for the hinges on the other side of the door with much longer screws. This re-enforces the other side of the door which normally people overlook (doors can be busted from BOTH sides in case preppers are not aware).
Next I bought a katy bar for around $100 and installed it. My door is now kick-proof and batter ram-proof. SIDE NOTE: If you want a military-grade blast-proof door you'll need a thick solid steel door and you'll need to replace the 2x4 pinewood door frame with a normal 4x4 and then re-enforce the whole 4x4 with stainless steel and angle brackets for where the top casting and the bottom threshold meets. Then follow all the steps mentioned such as installing multiple deadbolts (several inches away from the doorknob), long strikeplate, the katybar, door hinge re-enforcement (longer screws).