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ANSI lock function codes describe exactly how a lock operates, independent of manufacturer. Cylindrical locks (ANSI A156.2) use F75 through F110. Mortise locks (ANSI A156.13) use F01 through F30. The same functional behavior has different codes in each system: F84 cylindrical equals F05 mortise (both classroom function). Specifying F84 for a mortise lock is a common error. Key functions: F75/F01 passage (no locking), F76/F19 privacy (inside privacy button, emergency key outside), F82/F04 office (push button inside, key outside), F84/F05 classroom (key locks outside lever from corridor only), F86/F07 storeroom (outside lever always rigid, key to enter), F110 classroom security intruder (inside key locks outside lever from inside, no corridor exposure during lockdown). Functions are factory-set and cannot be changed in the field.
A hardware schedule is only as useful as the person reading it can interpret its function codes. Ordering an F82 (office function) instead of an F86 (storeroom function) for a pharmaceutical storage room eliminates the security the room was designed to provide. Ordering an F84 classroom function on a school project in a state with classroom security laws fails the inspection and generates a hardware change order that costs multiples of the difference in lock price. This guide explains every major ANSI function code, the cylindrical vs mortise numbering discrepancy that causes the most specification errors, the Schlage ND Series suffix system, and the classroom function evolution from F84 to F110 that affects every K-12 project.
Browse Schlage commercial lock parts by function at SecurityParts.com: Schlage ND Series and ALX Series cylindrical lock parts, Schlage L Series mortise lock parts, Schlage commercial hardware catalog, and the complete Allegion parts catalog.
Why ANSI Function Codes Exist and How the System Works
The ANSI lock function code system was created to allow hardware schedules to specify door lock behavior without requiring the specifier to name a particular manufacturer. An architect writing a hardware schedule can specify "F84 classroom function, Grade 1, 2-3/4 inch backset" without selecting a brand. The general contractor can then source that function from any BHMA-certified manufacturer because the behavior is standardized.
This works because ANSI function codes describe the mechanical behavior from the perspective of the occupant: which lever is free, which requires a key, what a push button or toggle does, and what state the lock is in when no action has been taken. The internal mechanism that produces this behavior varies by manufacturer, but the behavior it produces is consistent across all BHMA-certified products with the same function code.
The Two Numbering Systems: Cylindrical vs Mortise
This is where most hardware schedule errors originate. Cylindrical locks (bored locks, ANSI A156.2) and mortise locks (ANSI A156.13) use completely separate numbering systems for the same functional behaviors:
| Function Name | Cylindrical Code (A156.2) | Mortise Code (A156.13) | Schlage ND Suffix | Schlage L Series Suffix |
|---|---|---|---|---|
| Passage | F75 | F01 | ND10 | L9010 |
| Privacy | F76 | F19 | ND40 | L9040 |
| Office / Entrance | F82 | F04 | ND44 | L9044 |
| Classroom | F84 | F05 | ND70 | L9070 |
| Storeroom | F86 | F07 | ND80 | L9080 |
| Asylum / Institution | F87 | F30 | ND82 | L9082 |
| Vestibule / Apartment | F88 | F09 | ND60 | L9060 |
| Classroom Security (Intruder) | F110 | F32/F33 | ND78 | Varies |
A hardware schedule that lists "F84 classroom" for a door with a mortise lock is an error. The correct code for a mortise classroom function is F05. If you order a Schlage L9070 (mortise classroom) when the schedule says F84, the product is correct but the specification contains a cylindrical code applied to a mortise product. The mortise equivalent of F84 is always F05.
Non-Keyed Functions: Passage and Privacy
What it does
Both levers always retract the latch. There is no locking mechanism. The door can be pushed open from either side without any key, credential, or action. The latch retracts when either lever is turned.
Where it is used
Interior corridor doors that do not require any locking (open office areas, non-secured stairwells, maintenance corridors). Passage function is also the "unlocked mode" that some other functions (like F82 office) can be toggled into.
What it does
Inside trim has a push button or thumbturn that engages a bolt or lever-blocking mechanism, preventing the outside lever from operating. When the inside privacy device is engaged, the outside lever is locked. An emergency key (or a tool through an emergency hole in some cylindrical versions) allows emergency entry from outside. The inside lever always retracts the latch for egress.
Where it is used
Restrooms, individual offices where the occupant needs privacy without a key, fitting rooms, healthcare exam rooms. The emergency key feature satisfies life safety requirements by ensuring the occupant can never be permanently trapped inside.
Medium-Security Keyed Functions: Office and Entrance
What it does
Both levers retract the latch unless the outside lever is locked by a push button on the inside face of the lock or by a key from outside. When the push button is engaged, the outside lever is locked. Turning the inside lever OR inserting and turning the key from outside unlocks the push button and restores free operation. The inside lever is always free for egress regardless of push button state.
Where it is used
Individual offices that need to be locked during meetings or after hours. The push button allows occupants to lock the office from inside without a key, and a single lever operation (from inside) releases the lock. The key from outside is the entry method when the office is unoccupied and locked.
The security gap that F82 creates in some applications
F82 has a push button inside. When the office is unoccupied and locked, the outside lever is secure. But the push button means any person who knows about it can lock the door from inside to prevent access by authorized staff. In high-security or healthcare applications where staff must always have access, F82's inside push button is a vulnerability. F84 or F86 should be specified instead of F82 when inside lock control by unauthorized occupants is a concern.
High-Security Keyed Functions: Classroom and Storeroom
What it does
Both levers retract the latch unless the outside lever is locked. The outside lever is locked or unlocked by inserting and turning a key in the outside lever cylinder from the corridor side. The inside lever is always free for egress. There is no push button or toggle inside: the function cannot be changed from inside the room.
How the passage mode works
When a key is turned in the outside cylinder, it toggles the outside lever between locked and passage mode. In passage mode, both levers retract the latch freely. This is how classrooms are set for the school day: a staff member with a key uses the outside cylinder to put the lock in passage mode in the morning and locked mode at the end of the day.
The lockdown limitation
In F84/F05, the outside lever can only be locked from outside the room (in the corridor). During an active threat lockdown, a teacher must open the door and expose themselves to the corridor to lock the outside lever. This is the safety gap that F110 was designed to eliminate.
Browse Schlage ND70 Series F84 classroom cylindrical lock parts and Schlage L9070 F05 classroom mortise lock parts at SecurityParts.com.
What it does
The outside lever is permanently rigid. It cannot be turned under any condition from outside without a key. A key in the outside cylinder simultaneously retracts the latch and allows the lever to turn, providing entry. The inside lever is always free for egress. There is no passage mode, no push button, and no toggle: the outside lever cannot be placed in a freely operable state.
Why F86 is the correct specification for secured storage
F82 (office function) has an inside push button that can lock the door, but the outside lever can also be in a freely operable (unlocked) mode when the push button is not engaged. Any time the room is occupied without the push button engaged, the door is freely accessible from outside. F86 has no unlocked mode for the outside lever: the room is always key-access from the outside, whether occupied or not. This eliminates the risk of someone propping the door open or forgetting to engage the push button, leaving a secured room temporarily accessible.
Applications
Pharmaceutical storage, server rooms, cash rooms, records storage, electrical and mechanical rooms, evidence rooms, any space requiring key control at all times. Also the correct function for emergency stairwell doors in buildings requiring key-controlled stair reentry.
Browse Schlage ND80 Series F86 storeroom cylindrical lock parts at Security Parts.
Classroom Security: The F84 to F110 Evolution
The original F84/F05 classroom function was designed for a different threat environment: keeping students from locking each other out of classrooms, not protecting teachers during active threat events. After Sandy Hook (2012) and subsequent legislative action across multiple states, a new classroom security function was needed that allowed inside lockdown without corridor exposure.
What it does
Both levers retract the latch in the unlocked state. A key in either lever (inside or outside) locks or unlocks the outside lever. The inside lever remains free for egress at all times regardless of outside lever state. This allows a teacher inside the room to lock the outside lever using their key in the inside cylinder, without opening the door or entering the corridor.
How lockdown works with F110
During an active threat: teacher inserts key in inside cylinder, rotates 180 degrees counterclockwise, removes key. Outside lever is now locked. Door is secured from inside without any corridor exposure. To unlock: key in either lever, 180 degrees clockwise.
State classroom security law requirements
Many states have enacted classroom security legislation following mass shooting events at schools. California SB 1384 and similar laws in other states require classroom locks to allow locking from inside the room without opening the door. This effectively mandates F88, F90, or F110 functions. Specifying F84 on a school project in a state with these requirements results in a failed inspection and a hardware change order. Always verify state and AHJ requirements before finalizing the function code on any K-12 project.
F88/F09 Vestibule Function: The F110 Alternative for Apartment and Vestibule Applications
F88 (cylindrical vestibule) and F09 (mortise vestibule) allow the inside lever to lock the outside lever, but the inside lever also always allows egress. F88 is similar to F110 but the inside cylinder operation differs slightly: in F88, the inside key or toggle controls the outside lever, while in F110, a key in either lever controls the outside lever. F88 is also specified for apartment corridors and building vestibules where residents need to lock the corridor-side lever from inside their unit. In some school security applications, F88 is accepted where F110 is not specifically required.
Maximum Security and Specialty Functions
What it does
Both levers are always rigid. Neither lever can retract the latch from either side under any condition without a key in the respective cylinder. A key in the outside cylinder retracts the latch for entry. A key in the inside cylinder retracts the latch for egress. No lever-based egress is available.
Where it is used
Behavioral health facilities, psychiatric units, secure detention areas, and any environment where free egress capability (the ability to open the door from inside without a key) is not required or would compromise patient or inmate management. This is the most restrictive function: it eliminates the "inside lever always free" that all other functions maintain.
Schlage ND Series Function Suffix Quick Reference
| ND Suffix | ANSI Function | Common Name | Inside Lever | Outside Lever |
|---|---|---|---|---|
| ND10 | F75 | Passage | Always free | Always free |
| ND40 | F76 | Privacy | Free; privacy thumbturn | Locked when privacy engaged |
| ND44 | F82 | Office / Entrance | Always free; push button | Free or locked by push button |
| ND70 | F84 | Classroom | Always free; no lock control | Locked/unlocked by key from outside only |
| ND78 | F110 | Classroom Security | Free; inside key locks outside | Locked/unlocked by key from either side |
| ND80 | F86 | Storeroom | Always free | Always rigid; key only |
| ND82 | F87 | Institution / Asylum | Rigid; key to exit | Rigid; key to enter |
| ND60 | F88 | Vestibule / Apartment | Free; inside key locks outside | Locked by inside key; key from outside |
Browse Schlage ND Series parts by function suffix at Security Parts.
Five Specification Errors That Generate Hardware Change Orders
Error 1: Writing F84 (cylindrical code) in a mortise lock hardware schedule
F84 is a cylindrical lock code. The mortise lock classroom function is F05. A hardware schedule listing F84 for mortise lock openings contains a cross-standard error that may not be caught until the product arrives.
Fix: Always use the standard-specific code: F84 for cylindrical (ND70 from Schlage), F05 for mortise (L9070 from Schlage). Cross-reference the table above when moving between cylindrical and mortise specifications.
Error 2: Specifying F84 on a K-12 school project in a state requiring F110
F84 does not allow inside lockdown without corridor exposure. Many states now require F88, F90, or F110 for classroom doors. A failed inspection generates a change order that costs more than the specification verification would have.
Fix: Verify applicable state classroom security code and AHJ requirements before finalizing the function code on any K-12 project. When in doubt, specify ND78 (F110) and note the inside indicator requirement separately.
Error 3: Specifying F82 (office function) for secured storage rooms
F82 has a push button inside that allows occupants to lock the door from inside. In an unoccupied secured room with F82, the push button must be engaged for the room to be secure. If an occupant leaves without engaging the push button, the room is freely accessible until someone re-locks it.
Fix: Specify F86 (ND80) for any room requiring key-controlled access at all times. F86 has no unlocked mode for the outside lever: the room is always key-entry from outside regardless of occupancy or push button state.
Error 4: Assuming the function can be changed in the field
A contractor ordering the wrong function and planning to "convert it in the field" will find that most cylindrical lock functions cannot be converted without replacing the entire chassis. The latch, cam, and spindle configuration is factory-set.
Fix: Order the correct function code from the hardware schedule before the product ships. If there is uncertainty about the correct function, call SecurityParts.com at 845-935-0301 for function code verification before ordering.
Error 5: Specifying F87 (asylum function) without AHJ approval for locked egress
F87 eliminates the inside lever's free egress function. Both levers require a key. This is not permitted in most occupancies without specific code compliance documentation and AHJ approval for controlled or locked egress arrangements.
Fix: Confirm the specific NFPA 101 or IBC code section that permits locked egress for the occupancy type before specifying F87. Document the code basis for the function selection on the hardware schedule.
Why Choose Security Parts for Schlage Commercial Lock Parts
Cylindrical vs mortise code discrepancy documented, F110 classroom security law context, ND78 inside indicator detail, function change impossibility explained, and same-day OEM shipping.
Cross-Standard Code Reference
We document the cylindrical vs mortise function code discrepancy that causes the most hardware schedule errors. F84 is cylindrical classroom. F05 is mortise classroom. Confusing them generates wrong-product orders on projects with mortise lock specifications.
F110 State Law Context
We document that many states now require inside-locking classroom capability (F88/F90/F110) and that specifying F84 on school projects in these states results in failed inspections. This fact is absent from all competitor parts supplier content.
F82 Storage Room Risk
We document the F82 push-button vulnerability in storage rooms: F82 has an unlocked mode that F86 does not. Pharmaceutical storage and high-value rooms specified as F82 instead of F86 have a security gap that is never documented at the parts ordering level.
Same-Day OEM Shipping
Schlage ND Series and L Series parts by function ship same day from US warehouses. Call 845-935-0301 or the contact page for function code verification before ordering.
What Makes Security Parts Different for Commercial Lock Function Parts
- We document the cylindrical vs mortise ANSI function code numbering discrepancy and its cross-reference table. F84 for a mortise lock application is wrong: the mortise classroom function is F05. This is the single most common hardware schedule error and is documented nowhere in competitor parts content.
- We document the state classroom security law context for F110: specifying F84 on school projects where state law requires inside-locking capability fails inspection and generates change orders. No competitor documents this at the parts purchasing level.
- We document the F82 push-button vulnerability: F82 can be in an unlocked mode. F86 cannot. Secured storage rooms specified as F82 instead of F86 have a security gap that no other parts supplier documents.
- We document the Schlage ND78 Know It's Locked indicator as a lockdown status verification tool. The indicator allows staff to confirm outside lever lock status from across the room without approaching the door, which is the specific improvement over F84 that addresses the lockdown verification problem.
- We carry Schlage ND Series cylindrical lock parts and Schlage L Series mortise lock parts for all major ANSI function codes, alongside the Falcon commercial hardware parts catalog and complete Allegion parts catalog.
- Free shipping on orders over $450. Same-day shipping from US warehouses on stocked parts. 30-plus years of commercial door hardware experience.
Frequently Asked Questions About Commercial Lock Function Codes
What is an ANSI lock function code and why does it matter?
An ANSI lock function code is a standardized number describing exactly how a lock operates: which lever is free, which requires a key, and what inside controls exist. The system is standardized across manufacturers so that an F84 from Schlage and an F84 from Sargent behave identically. Function codes matter because the wrong function creates either a security gap (F82 in place of F86 on a secured storage room) or a code violation (F84 on a school project requiring F110). Functions are factory-set and cannot be changed in the field without replacing the entire lock chassis.
What is the difference between cylindrical lock function codes and mortise lock function codes?
Cylindrical locks use function codes in the F75 and above range (F75, F82, F84, F86, F110). Mortise locks use function codes in the F01 through F30 range (F01, F04, F05, F07, F30). The same functional behavior has different codes in each system: F84 cylindrical equals F05 mortise (both classroom), F86 cylindrical equals F07 mortise (both storeroom). Writing F84 in a hardware schedule for a mortise lock application is a cross-standard error. Always use the code for the correct lock type.
What is the difference between the F84 classroom function and the F110 classroom security function?
F84 allows the outside lever to be locked or unlocked only from outside the classroom (corridor side). During lockdown, the teacher must open the door and expose themselves in the corridor to lock it. F110 allows either lever (inside or outside) to lock or unlock the outside lever, so the teacher can lock the door from inside without opening it or entering the corridor. Many states now require inside-locking capability (F88, F90, or F110) for classroom doors. Specifying F84 on a school project in a state requiring F110 fails the inspection.
What is the difference between the F84 classroom function and the F86 storeroom function?
F84 classroom can be toggled between locked and passage (free swing) mode by a key from outside. The room can be freely accessible when the key holder puts it in passage mode. F86 storeroom has no passage mode: the outside lever is permanently rigid and the room is always key-access from outside. F86 is the correct specification for pharmaceutical storage, server rooms, cash rooms, and any space requiring key control at all times. F84 is not appropriate for rooms that must never be in a freely accessible mode.
Can a lock function be changed in the field after installation?
For most cylindrical locks, no. The internal cam, spindle, and mechanism configuration that produces the function behavior is factory-set and cannot be rearranged in the field. Converting a Schlage ND70 (F84 classroom) to an ND80 (F86 storeroom) requires replacing the entire lock chassis. Some mortise locks offer limited field function conversion, but the base function is generally also factory-set. Order the correct function code before the product ships. Function code changes after installation typically require complete lock replacement.
How do I read the lock function column in a hardware schedule?
The function column in a hardware schedule lists either the ANSI code (F84, F86, F82) or a manufacturer-specific suffix (ND70, ND80, ND44 for Schlage ND Series). Cross-reference the suffix to the ANSI code using the manufacturer's function guide: ND70 equals F84, ND80 equals F86, ND78 equals F110. Confirm whether the schedule is specifying cylindrical or mortise hardware: the same ANSI function has different codes in each system. On school projects, verify state classroom security law requirements before accepting the scheduled function code, since many states have updated their requirements beyond F84.