Q. What does a rack bolt do?

Answer

Your wood door might require some further protection, which is where these hidden door security bolts come in handy. These bolts are often installed in pairs, with one located at the top of the door and the other at the bottom of the door. They are recessed into the door and sometimes referred to as rack bolts; also, the interior face of the door has a keyhole carved into it. The bolts are operated by a key that, when cranked, extends the bolts into the holes in the bottom and top of the door frame. These keeps are located on each side of the door frame. This offers a very easy and safe type of door security since it can only be accessible from the inside side of the door.