Types of Locks: A Guide to the 7 Most Common Locks
Locks come in many shapes, but most fall into a handful of familiar categories. Here are seven of the most common types and where you will find them.
1. Padlocks
Portable, self-contained locks with a shackle, used on gates, lockers, sheds and storage units. Many professional padlocks are rekeyable. See our padlocks.
2. Deadbolt Locks
A bolt that extends into the door frame and can only be retracted by a key or thumbturn, not by spring pressure — a key security upgrade for exterior doors. Available in single- and double-cylinder versions.
3. Knob Locks
Key-in-knob locks have the cylinder in the knob. They are common on residential doors but are generally not relied on as the sole lock on an exterior door.
4. Lever Handle Locks
Lever handles are easier to operate than knobs and are common in commercial buildings and for accessibility.
5. Cam Locks
A rotating cam secures cabinets, drawers, mailboxes and lockers. For filing cabinets, see the replacement filing cabinet lock kits.
6. Mortise Locks
Installed in a pocket (mortise) cut into the door edge, mortise locks are heavy-duty and common in commercial and older residential buildings. They use threaded mortise cylinders, often installed with a tool such as a mortise wrench.
7. Smart Locks
Electronic locks that open with a code, phone app, fob or fingerprint, often with a mechanical key override.
Frequently Asked Questions
What is the most secure type of lock for a home?
A quality deadbolt, properly installed, is the standard security upgrade for exterior doors.
What is the difference between a knob lock and a deadbolt?
A knob lock uses a spring latch; a deadbolt uses a bolt that cannot be pushed back without the key or thumbturn.
What are mortise locks used for?
Heavy-duty applications, especially commercial doors and older buildings.