Mortise locks are installed into a rectangular pocket cut out of the edge of a door. The term mortise refers to a hole or recess cut that allows the lock to be inserted. Mortise lock bodies look much different than cylindrical locks and allow for more working mechanics inside. Mortise locks have more lever and trim styles than most cylindrical locks providing more flexible designs.

Mortise Lock Durability

Grade 1 mortise locks are tested to meet 1,000,000 cycles whereas cylindrical locks are only required to meet 800,000 cycles to be certified as Grade 1. Grade 1 mortise locks are put through an extra level of abusive tests to ensure they meet higher standards of durability. The locking mechanisms are located inside a metal case and inside the door which further protects it from damage.

Mortise Lock Functionality

Mortise lock bodies have room for the standard locking functions as well room for the addition of deadbolts, thumbturns, indicators, and other options. This provides more locking functions than cylindrical locks. Schlage cylindrical locks, for example, have a little over 29 functions available while Schlage mortise locks have over 49 functions available.

Standard ANSI/BHMA functions are available as well as functions that the brand may offer exclusively. Electric options such as request to exit and electric locking or unlocking can be specified as well.

Mortise Lock Design Flexibility

Most mortise lock manufacturers offer trim styles with roses and escutcheons available. Also, due to their use in higher-end projects, mortise locks often have many custom lever designs to meet the aesthetic requirements of a space. Schlage L-series mortise locks are available with 13 finishes and 32 lever styles. Optional thumbturns and occupancy indicators also provide function and form that will impress.

Many brands supply their locks handed. However, handing can be changed in the field if necessary. Handing is critical for the door preps due to the cut out for the cylinder that is installed into the lock body through the face of the door.

So, if it isn’t clear yet, the reason you should use mortise locks is if you want a lock that requires little to no maintenance, if you require standard or custom functions including deadbolts, and if you want more lever and trim design options. Mortise locks combine durability, functionality, and design flexibility in one lock body for a robust product offering to meet the needs of your project.