A mortise lock fits into a deep pocket cut into the door edge, rather than through a round bore like a cylindrical lockset. That construction is why mortise locks are the standard for commercial buildings, schools, and apartment entries: the heavy cast or steel lock body withstands decades of high traffic, integrates deadbolt and latch in one unit, and offers far more functions (entry, classroom, storeroom, privacy, passage) than a cylindrical lock.
When choosing a mortise lock, start with the function you need on that door. An office function locks from outside while always allowing free egress. A storeroom function is always locked outside. An entrance function adds a deadbolt for after-hours security. Then confirm handing (left or right hand, regular or reverse bevel), backset, and whether you need it keyed into an existing system. Most of the mortise locks we sell accept standard or high-security cylinders, so you can upgrade key control without changing the lock body.
We carry Grade 1 commercial mortise locks from Marks USA, Sargent, Corbin Russwin, Yale, and others, including ornamental and storm-door mortise locks if your application is a gate or security screen door. If you're replacing an old mortise lock, send us a photo and measurements and we'll match it.
