Rim knobs and mortice knobs are two different types of door knobs used for various applications. Here’s the difference between the two:

Rim knobs are surface-mounted door knobs that are fixed onto the surface of the door. They are attached to a backing plate or rosette, which is secured to the door surface using screws. Rim knobs are typically used on doors where the lock mechanism is housed separately in a rim lock or night latch, hence the name “rim” knob. The lock mechanism is usually mounted on the surface of the door rather than being recessed into it.

Mortice knobs, on the other hand, are designed for doors with a mortice lock or latch. A mortice lock is a type of lock that is recessed or “morticed” into the edge of the door. Mortice knobs are installed by creating a hole or mortice in the door to accommodate the lock mechanism, and the knob is then fitted into this recess. The mortice lock provides a more secure and flush fitting, as the lock is concealed within the door.

In summary, the main difference between rim knobs and mortice knobs lies in the installation and the type of lock they are compatible with. Rim knobs are surface-mounted and used in conjunction with rim locks, while mortice knobs are recessed into the door and used with mortice locks. The mortice knob controls the lock or latch whereas the rim knob doesn’t.  The choice between the two depends on the type of lock and the aesthetic preferences for your door.  View the Atlantic range of Mortice Knobs here:  https://atlantichandles.com/?s=mortice+knob