How Does A Doorknob Work?

Doorknobs come in different finishes, styles, and types to match your home's aesthetic, but how does this important hardware work? The inner workings vary based on the type of doorknob you have. Understanding the differences can help you choose the best type or troubleshoot an issue with a current doorknob.

A standard doorknob lock set consists of door parts including a pair of knobs, one on each side of the door, that are connected through the door by a spindle and held together by mounting bolts. The spindle runs through the latch bolt, which is inside the door perpendicular to the spindle. The latch bolt is connected to the latch, which protrudes from the edge of the door and engages the door frame, preventing the door from opening.

When either knob turns, it rotates the spindle. The spindle retracts the latch and allows the door to open. In most cases, the spindle is spring-loaded so the latch springs back into the closed position when you release the doorknob.

The face plate is a flat metal plate on the edge of the door through which the latch protrudes. It's secured to the door with screws and holds the latch in place. The metal strike plate is attached to the door frame opposite the latch; its job is to guide the latch into its receptacle in the frame and hold it securely closed.

Interior passage doorknob sets aren't equipped with locks. Both knobs always turn freely, and either knob can retract the latch.

Privacy knob sets for interior doors are equipped with a keyless lock on the inside knob. Turning or pushing a button on the inside knob prevents the outside knob from turning and opening the door, but turning the inside knob releases the lock and allows the door to open.

Entry knob sets are typically equipped with a keyed lock on the outside knob and a button-activated lock on the inside knob. The button lock on the inside knob works the same way that it does on a privacy knob set, but the door can also be opened from the outside with the use of a key. These types of doorknobs go on front doors or back doors and often feature a separate deadbolt for added security.

As an alternative to knob sets, some lock sets are equipped with levers or grip handles rather than doorknobs. In a lever set, a lever handle rotates the spindle and retracts the latch when the lever is pushed downward. In a handle set, the latch retracts when a thumb piece on the handle is depressed, engaging an internal lever, which in turn rotates the spindle and opens the latch.