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 to the various overlap in function terminology, a number of the mortise lock functions do not carry an ANSI ‘F' label. Looking through the catalog of any of the major lock manufacturers will reveal a variety of functions without a corresponding ‘F' label. For example, in the current Schlage full-line catalog, only 27 of the 50 mortise lock functions use the ‘F'-series number. The non-‘F'-labeled mortise locks were developed for a specific application(s).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.
Following is a compilation of the most common functions and the corresponding American National Standards Institute (ANSI) function numbers. The ANSI function numbers are a way to identify standardized (and accepted) operation or function of a mortise lock.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.
The terminology describing each function is also compiled from the various manufacturers' technical literature and industry accepted terms. Before purchasing a specific manufacturer's mortise lock, read how the lock operates, making sure it fit the requirements of the door.For the purpose of this article and the accompanying chart, we will concentrate on the non-electrified ANSI listings of F01 through F35.
PASSAGE / CLOSET (ANSI F01): Latch is retracted by knob or lever from either side at all times.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.
ENTRANCE / OFFICE (ANSI F04): Latchbolt is retracted by knob or lever from either side unless outside is locked by toggle on face of lock. In that case, the latchbolt is retracted by key outside and knob or lever inside. On some makes, dual position thumb turn replaces toggle. Auxiliary latch deadlocks latchbolt. Inside knob or lever is always free.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.
CLASSROOM HOLDBACK / HOSPITAL (ANSI F06): 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. Latchbolt can be held back in retracted position by key outside.STOREROOM / SERVICE CLOSET (ANSI F07): Latchbolt is retracted by key outside and by knob or lever inside. Outside knob or lever is always locked. Inside knob or lever is always free. Auxiliary latch deadlocks latchbolt.
ENTRANCE / STOREROOM (ANSI F08): Latchbolt is retracted by knob or lever from either side, except when outside is locked by thumb turn. Deadbolt is retracted by key outside and by thumb turn inside. Deadbolt deadlocks latch.VESTIBULE / ENTRANCE / EXIT / PUBLIC RESTROOM (ANSI F09): Latchbolt is retracted by knob or lever from either side unless outside is locked by key from inside cylinder. Then latchbolt is retracted by key outside. Inside knob or lever is always free. Auxiliary latch deadlocks latchbolt.
ENTRANCE (ANSI F10): Latchbolt is retracted by knob or lever from either side, except when outside is locked by toggle on lock face. Dead latch is retracted by key outside and by knob or lever inside.DORMITORY (ANSI F11): Latchbolt is retracted by knob or lever from either side except when outside is locked by toggle or projected deadbolt. Deadbolt is operated by key from either side. Inside knob or lever retracts dead latch and deadbolt simultaneously, leaving outside locked. Deadbolt deadlocks latch.
DORMITORY / ENTRANCE / FRONT DOOR (ANSI F12): Latchbolt by knob or lever from either side except when projected deadbolt locks outside. Deadbolt deadlocks latch. Deadbolt operated by key outside and by thumb turn inside. Inside knob or lever retracts dead latch and deadbolt simultaneously, leaving outside locked.CORRIDOR / DORMITORY (ANSI F13): Latchbolt by knob or lever from either side except when projected deadbolt locks outside and deadlocks latch. Deadbolt operated key outside and by thumb turn inside. Key outside retracts deadbolt, then latch. Inside knob or lever retracts dead latch and deadbolt simultaneously, automatically unlocking outside knob or lever.
STOREROOM / UTILITY / STOREFRONT DOOR (ANSI F14): Latchbolt operated by knob or lever inside and by key outside. Outside knob or lever is always rigid, inside knob or lever is always free. Alternate: Latchbolt is operated by knob or lever from either side. Deadbolt is operated by key from either side.HOTEL / MOTEL w/ INDICATOR (ANSI F15): Inside knob or lever is always free, outside knob or lever is always rigid. Latchbolt operated by knob or lever inside, by key outside. All keys except emergency bypass keys are shut out when deadbolt is projected by inside thumb turn. Inside knob or lever retracts dead latch and deadbolt simultaneously leaving outside locked. Auxiliary latch deadlocks latchbolt. Furnished with visual "Occupied/Do Not Disturb" indicator button or sign plate.
DOUBLE CYLINDER DEADLOCK (ANSI F16): Deadbolt operated by key from either side, no knob or lever trim. Should only be used on rooms with more than one exit.Caution: Double cylinder locks on any door including a residence, which is used for egress, are a life safety hazard in times of emergency. Their use is NOT recommended. Installation should be in accordance with existing fire, life and safety codes only.
CYLINDER DEADLOCK / CLASSROOM (ANSI F17): Deadbolt operated by key outside, by thumb turn inside, no knob or lever trim.CYLINDER DEADLOCK / CLASSROOM (ANSI F18): Deadbolt operated by key outside, no inside operation.
PRIVACY / BEDROOM / BATHROOM (ANSI F19): Latch is retracted by knob or lever from either side. Deadbolt is operated by thumb turn inside or emergency release tool outside. Turning inside knob or lever retracts the latchbolt and deadbolt simultaneously, unlocking outside knob or lever.ENTRANCE / DORMITORY / APARTMENT (ANSI F20): Latchbolt is retracted by knob or lever from either side unless outside is locked by thumb turn or toggle on door edge. Deadbolt is thrown by thumb turn, automatically locking outside knob or lever. Outside remains locked until thumb turn is restored to vertical position or toggle on door edge is reversed. Auxiliary latch deadlocks latchbolt.
DORMITORY / BEDROOM / ENTRANCE / STOREROOM (ANSI F21): Latchbolt is operated by knob or lever from either side. Deadbolt is operated by key from outside and by thumb turn inside. When deadbolt is projected, key outside will retract deadbolt, then latchbolt.BATH / BEDROOM / PRIVACY (ANSI F22): Latchbolt is retracted by knob or lever from either side except when outside is locked by inside thumb turn. Turning inside knob or lever, closing door, or operating outside emergency release unlocks outside knob. Available with thumb turn both sides.
STOREROOM (ANSI F24): Latchbolt by thumb piece either side except when outside thumb piece is locked by toggle on lock face, then by key outside. Deadbolt operated by key from either side. Deadbolt dead locks latch.INSTITUTIONAL PRIVACY (ANSI F26): Latchbolt by knob or lever from either side except when outside is locked by inside thumb turn. Latch is deadlocked by auxiliary latch. Key from outside retracts latch. When outside is locked, inside knob or lever retracts latch, automatically unlocking outside.
DEADLOCK (ANSI F29): Deadbolt operated by key outside. Inside thumb turn will retract but will not project deadbolt.INSTITUTION (ANSI F30): Both outside and inside knobs or levers are always rigid. Auxiliary latch deadlocks latch. Latch is retracted by key from either side.
EXIT (ANSI F31): Latchbolt is retracted by knob or lever inside, by key outside. Outside has non-removable blank trim or no trim.SIDEBAR SO, WHAT'S NEW?
As old and dependable as the mortise lock is, there are new developments. With the recent focus on security after the Sept. 11h, 2001, terrorist attack, be sure to familiarize yourself with the newest functions designed to secure schools, dormitories and classrooms.
DORMITORY (ANSI F33): Latchbolt is retracted by knob or lever from either side when projected deadbolt locks outside knob or lever and deadlocks latch. Deadbolt and latch from either side by key. Inside knob or lever retracts latch and deadbolt simultaneously, automatically unlocking outside knob or lever.
INTRUDER DEADBOLT (ANSI F34): Latchbolt is retracted by knob or lever from either side. Deadbolt is operated by key from either side. Inside knob retracts latch and deadbolt simultaneously, automatically unlocking outside knob. Auxiliary latch deadlocks latch.STOREROOM (ANSI F35): Latchbolt is retracted by knob or lever from either side except when outside is locked by toggle on lock face, then by key from outside. Deadbolt operated by key from either side. Deadbolt deadlocks latch.
Beyond ANSI F35 and the electrified mortise locks, there are mortise locks developed for specific applications. These mortise locks may or may not have an ANSI number. Several examples include:- A mortise lock that has a lock cylinder on the exterior only. No lock cylinder on the interior. No knob or lever on the interior or exterior.
- A mortise lock whose latchbolt is retracted by knob or lever from either side unless outside is locked by key from either side. When locked, latchbolt is retracted by key from outside and by knob or lever inside. Retracting latchbolt by key unlocks outside knob or lever. Auxiliary latch deadlocks latchbolt when door is locked.
- A mortise lock whose latchbolt is retracted by knob or lever from either side unless outside is locked by key from either side. When locked, latchbolt is retracted by key from outside and by knob or lever inside. Retracting latchbolt by key unlocks outside knob or lever. Auxiliary latch deadlocks latchbolt when door is locked. Depress inside knob or lever and turn key 360 degrees for holdback feature.
