Hinge Bolts
Door hinges are a popular target for attack by burglars, in some cases, as little as a well positioned kick can be enough to force a door off its hinges. Hinge bolts can be used to bolster a door against these sorts of attacks.
Drilled into the hinge side of a door, hinge bolts nestle into specially drilled holes in the door frame when closed, securing the hinge side of the door to the frame. They are commonly used in conjunction with rack bolts.