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Starting out, most locksmiths quickly learn how to duplicate keys, rekey cylinders and take apart knob locks. Then one day a customer walks in with a brown paper bag full of parts. It was the dreaded situation of the ‘exploded' mortise lock. For many locksmiths, a mortise lock is no problem when the cover is on and all the parts are in their proper order. However, an open case means flying springs, jumping levers, dislodged hubs and errant latches.
As experience grows, we learn that mortise locks are not to be feared. They are cleverly designed mechanical devices produced to secure our residential and commercial doors. As complex as some of these mortise locks can be mechanically, they each fall into one of a limited number of operational functions.
As you will see in the following list, the sheer number of mortise lock functions far exceeds those of standard commercial knobsets and leversets. Many mortise lock functions cover more than one category. For example, an ANSI F09 function is listed as Vestibule, Entrance, Exit and Public Restroom.
In fact, seven ANSI functions use the term ‘Entrance' in the description, but each works in a slightly different way. Therefore, it is vitally important to understand the needs of your customer before simply grabbing a lock listed as ANSI F09. Fully read and comprehend the details of the function specifics printed in the manufacturer's catalog for a given brand of lock. Each lock manufacturer has its own design for a specific function that is not compatible with a different manufacturer.
In addition, many mortise functions are available in an electrified version. Like other electrified locks, they can be ordered for fail-safe or fail-secure operation. As was recently brought to light in a tragic Chicago high-rise fire, a stairwell door lock should automatically unlock in an emergency. If a standard fail-secure electric strike was used, a loss of power could mean a non-latched, free-swinging door. This could result in the fire spreading rapidly and cause further danger and loss of life. In a fire/life/safety application, a stairwell door must be positive latching at all times.
In the recent Chicago fire, stairwell doors were locked and stayed locked from inside the stairwell, even in the fire alarm status. Many people perished because they were caught in smoke-filled stairwells and could not get past the fire-affected floors or could not get out to another unaffected floor.
Note: Always check with your local Authority Having Jurisdiction (AHJ) to clarify local codes and requirements.
To simplify the different manufacturers and their product numbers, we have included a cross-reference table showing Arrow, Corbin/Russwin, Dorma, Falcon, Marks, PDQ, Sargent, Schlage and Yale factory part numbers for these functions. As a note, Arrow, Corbin/Russwin, Dorma, Falcon, and Sargent mortise locks have multiple sets of product numbers. For this table, we will either use a generic portion of the product numbers or for example, Sargent; we made a choice to use the lever function (8200 Series) numbers. This is partly because, for most installation, we will use levers to accommodate ADA. For Sargent knob mortise locks, replace the ‘82' in each number with ‘78' to indicate the 7800 Series knob trim.
For the purpose of this article and the accompanying chart, we will concentrate on the non-electrified ANSI listings of F01 through F35.
PRIVACY / BEDROOM / BATHROOM (ANSI F02): Latch is retracted by knob or lever from either side, except when outside is locked by thumb turn inside. Anti-panic operation - Turning inside knob or lever retracts the latchbolt (or deadbolt if so equipped), automatically unlocking outside knob or lever. Deadbolt or dead latch is operated by thumb turn inside or emergency release tool outside.
CLASSROOM (ANSI F05): Latchbolt is retracted by knob or lever from either side unless outside is locked by key outside. Unlocked from outside by key, inside knob or lever is always free for immediate exit. Auxiliary latch deadlocks latchbolt.
The Classroom Function enables the instructors and staff to lock and unlock their classrooms to best safeguard the students and their property. Students cannot lock the classrooms but can always...
These locks protect classrooms because the teacher is able to lock the exterior trim without leaving the interior of the classroom.