Technical Foundation
What Is a Door Lock?
Commercial door locks are rated by ANSI/BHMA grade — Grade 1 (highest durability, rated for heavy commercial and industrial use), Grade 2 (commercial, moderate traffic), and Grade 3 (residential/light commercial) — based on standardized cycle testing, strike testing, and torque/impact resistance. Lock function (entry, storeroom, classroom, passage, privacy) describes how the lock behaves from each side — a storeroom function lock, for example, is always locked from the outside and requires a key to enter, while the inside lever always allows exit without a key, a requirement often driven by life-safety egress codes.
Keying systems range from a single standalone key to a full master-key hierarchy where a facility's individual keys open only their own door, sub-master keys open a group of doors, and a grand master opens the entire facility — this hierarchy needs to be planned before ordering locks, since retrofitting a keying system after installation is far more disruptive than specifying it up front. Fire-rated doors require fire-listed hardware specifically tested as an assembly with that door, and a non-rated lock installed on a fire door voids the door's rating.
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| Spec | What It Means | Why It Matters |
|---|---|---|
| ANSI/BHMA Grade | Grade 1, 2, or 3 | Determines cycle life and resistance to forced entry — Grade 1 for heaviest commercial/industrial traffic |
| Lock Function | Entry, storeroom, classroom, passage, privacy | Defines locking behavior from each side of the door, often tied to egress code requirements |
| Keying System | Standalone, master keyed, grand master keyed | Must be planned facility-wide before ordering — determines key hierarchy and access control structure |
| Fire Rating | Listed for fire-rated door assemblies | Required by code on fire doors — non-rated hardware voids the door's fire rating |
| Backset & Door Prep | 2-3/8 in or 2-3/4 in backset, ANSI strike prep | Must match the door's existing bore and prep pattern for retrofit installations |
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Applications
Where Door Locks Get Used
Door locks are specified anywhere access to a space needs to be controlled, secured, or restricted according to a defined function and traffic level.
Commercial Office Buildings
Grade 1 and 2 locksets on entry, office, and storeroom doors across varied traffic levels.
Industrial Facilities & Warehouses
Heavy-duty Grade 1 locks and exit devices on high-traffic and equipment room doors.
Educational Institutions
Classroom-function locksets allowing lockdown from inside while permitting free exit.
Healthcare Facilities
Privacy and access-controlled locks meeting infection control and life-safety requirements.
Multi-Tenant & Residential Buildings
Keyed and master-keyed locks managing access across individual units and common areas.
Government & Secure Facilities
Electronic and high-security mechanical locks with strict access control and audit requirements.
FAQ
Door Locks Questions, Answered
What's the difference between ANSI/BHMA Grade 1, 2, and 3 locks?
Grade 1 locks pass the most demanding cycle, strike, and torque testing and are specified for heavy commercial and industrial traffic and higher security needs. Grade 2 covers moderate commercial traffic with somewhat less stringent testing requirements. Grade 3 is the lightest duty, typically residential-grade hardware not intended for high-traffic commercial doors. Choosing based on actual expected door cycles and security needs avoids premature failure from an undersized grade.
What does 'storeroom function' mean on a lockset?
Storeroom function means the outside lever is always locked and requires a key to enter, while the inside lever always allows free exit without a key, regardless of the lock state. This function is common on doors like storage or equipment rooms where controlled entry is needed but code requires unrestricted exit — different from entry function, where the outside can be locked or unlocked as needed by a user with a key.
How does master keying work, and when should I plan for it?
A master key system uses a hierarchy of keys — each door's individual key opens only that door, a sub-master opens a defined group of doors, and a grand master opens every door in the system — allowing tiered access control across a facility. This needs to be planned and specified when locks are ordered, since the keying hierarchy is built into the cylinder's pinning at manufacture; adding master keying after individual locks are already keyed separately typically requires re-keying every cylinder.
Why does a fire-rated door need fire-listed hardware specifically?
Fire doors are tested and rated as a complete assembly — door, frame, and hardware together — and the hardware's ability to hold the door closed and latched under fire conditions is part of that certification. Installing hardware that isn't listed for that specific fire rating voids the door's rating regardless of how well the lock otherwise performs, which is a common code compliance issue during inspections.
What's the difference between a cylindrical lockset and a mortise lockset?
A cylindrical lockset installs into two round bored holes in the door and is generally faster and less expensive to install, common on moderate-traffic commercial doors. A mortise lockset installs into a rectangular pocket cut into the door edge, offering a more robust mechanism and typically higher security and durability — standard on higher-traffic or higher-security commercial and institutional doors.
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