Mortise Lock vs. Cylindrical Lock: Which One is Right for Your Project?

Cylindrical Locks: These are the most common locks found in residential homes. They are installed by drilling two holes in the door: a large hole for the knob/lever and a smaller hole in the edge for the latch. They are generally lighter and easier to install.

Mortise Locks: These require a rectangular pocket (the mortise) to be cut into the edge of the door. The lock body—a sturdy metal box containing the latch and deadbolt mechanism—slides into this pocket. This design is traditional, robust, and commonly seen in commercial buildings and older, high-quality homes.

Durability: High-quality mortise locks are built to withstand high-frequency usage, often exceeding 500,000 cycles. This makes them ideal for office doors, hotels, and entryways.

Functionality: Mortise locks often combine a latch and a deadbolt into one unit, operated by a thumb turn or key, offering superior holding power compared to the standard spring latch of a cylindrical lock.

New Construction: If you are building from scratch, installing a mortise lock is straightforward.

Retrofitting: Replacing a cylindrical lock with a mortise lock is difficult because it requires cutting a large pocket into the existing door, which can weaken the door structure if not done correctly. Conversely, replacing a mortise lock with a cylindrical one leaves unsightly gaps that need to be filled.

Choose Cylindrical for interior bedroom/bathroom doors or budget-friendly residential projects where ease of installation is key.

Choose Mortise for front entry doors, commercial spaces, or heavy solid-wood doors where security and aesthetic weight are important.