The Complete Handbook of Door Hardware

Chapter 1: Understanding Door Hardware

A door hinge is a bearing. A lock is a blocking device. A door closer is a hydraulic pump. These are not metaphors. If you keep this in your head as you read the rest of this book, most of the confusion and guesswork inherent in buying and installing hardware will disappear.

Door hardware is not a set of accessories you bolt onto a slab. It is an assembly of mechanical components, each designed to perform a specific task: support a panel, latch a panel, hold a panel open, force it closed, resist fire, or stop a person from breaking through. When you bring them together, each of those components behaves in relation to the door itself, the frame, the wall, and the movement of people through the opening. The purpose of this chapter is to give you a functional baseline for how that works in practice, before you start thinking about grades, brands, and finishes.

Let's start with the door itself. A typical interior door is between 1-3/8 and 1-3/4 inches thick, weighs about 30 to 50 pounds for hollow-core slab, and between 80 and 120 pounds for a solid hardwood or commercial metal door. It mounts to the frame with either two or three hinges. If the hinge is defective or misaligned, the door will sag, the latch will not align with the strike, and the lock or latch bolt rubs hard against the interior edge of the frame. This is the number