What Are the Different Types of Door Locks? A Complete Buyer's Guide

Choosing a door lock sounds simple until you're standing in front of a hardware schedule, a product catalog, or a door that keeps failing. The truth is there are more than a dozen distinct lock types, and each one exists because a specific door, application, or security need demanded it.

This guide covers every major door lock type- what it is, how it works, where it belongs, and what to look for when buying. Whether you're outfitting a commercial building or replacing a worn-out lock at home, you'll know exactly what you need by the end.

About Door Locks and How They're Categorized

Door locks fall into three categories: mechanical design (how the lock body is built), function (how it operates when you use a key, lever, or credential), and grade (how well it performs under standardized testing).

The ANSI/BHMA grading system is the one that matters most for commercial buyers. Grade 1 is the highest- required on all primary commercial doors, corridors, and egress paths. Grade 2 suits lighter interior applications. Grade 3 is residential only and has no place in a commercial building spec.

Mortise Locks

A mortise lock fits inside a rectangular pocket cut into the door edge. The entire mechanism- latch, deadbolt, and internal parts- lives in a single steel case. Trim (levers and cylinders) mounts through the door face and connects to the case with through-bolts running the full thickness of the door.

That design is why mortise locks are the toughest option in commercial hardware. The steel case absorbs lateral force directly. There's no exposed spindle to shear under pressure. And because the deadbolt is part of the same body as the latch, you get full security in a single unit.

Best for: School corridors, hospital entries, government buildings, main building entries, any door with heavy daily traffic.

Brands to know: Schlage L Series, Sargent 8200 Series, Corbin Russwin ML2000, BEST 45H Series.

Standard: ANSI/BHMA A156.13 Grade 1- 1,000,000 cycles minimum.

Browse the mortise lock catalog at American Locksets.

Cylindrical Locks

Cylindrical locks install through two bored holes in the door face- a 2-1/8" hole for the lock body and a 1" hole for the latch. They're faster to install than mortise locks, cost less per opening, and still come in Grade 1 for commercial applications.

They're the most commonly used lock type in commercial buildings because they cover the majority of interior and secondary doors perfectly well. The trade-off is structural- on a door that gets hammered hundreds of times a day, the lighter chassis of a cylindrical lock wears faster than a mortise body. Save mortise for primary entries; cylindrical works great everywhere else.

Best for: Interior office doors, conference rooms, storage rooms, secondary entries with moderate daily use.

Brands to know: Schlage ND Series, Sargent 10 Line, Corbin Russwin CL Series, BEST 9K Series.

Standard: ANSI/BHMA A156.2 Grade 1- 1,000,000 cycles minimum.

Deadbolt Locks

A deadbolt is a bolt that only moves when you deliberately operate it- by key, thumbturn, or electronic credential. It has no spring action, so it can't be shimmed or pushed back by pressure on the bolt face.

There are two main types:

Single-cylinder deadbolt: Key outside, thumbturn inside. The inside thumbturn lets occupants exit without a key. Correct for exterior building doors and retail entries where overnight security matters.

Double-cylinder deadbolt: Key required on both sides. No thumbturn. Higher forced-entry resistance but creates an egress hazard if used incorrectly. Only appropriate on specific restricted-access doors where the local authority explicitly permits it- never on a required egress path.

Best for: Exterior doors as supplemental security, retail back-of-house entries, storage rooms.

Browse commercial deadbolts at American Locksets.

Knob Locks

Knob locks use the same basic mechanism as cylindrical locks but replace the lever with a round knob. They're largely obsolete in commercial settings because ADA Section 404.2.7 prohibits hardware that requires tight grasping, pinching, or twisting on accessible routes- which covers nearly every door in a public commercial building.

They still have a place in non-accessible utility closets and private spaces that aren't on required accessible routes. If you're upgrading hardware across a building, replace any knob lock on a public corridor or accessible route with lever hardware.

Best for: Non-accessible utility spaces only. Not suitable for public-use commercial doors.

Electrified Locks

Electrified locks are standard Grade 1 mortise or cylindrical locks with an integrated solenoid or motor that controls whether the outside lever works, based on a signal from an access control system, card reader, or remote switch.

Two functions define every electrified lock:

Fail safe (EL- Electrically Locked): Power holds the door locked. Lose power and the door unlocks. Right for egress corridors and fire alarm-integrated entries.

Fail secure (EU- Electrically Unlocked): Power allows entry. Lose power and the door locks. Right for server rooms, pharmacies, and any restricted area where losing power should never leave the door open.

This is not a reversible field decision on most models. Get the function right before you order. The Schlage L9095 is one of the few with a field-selectable switch if you need flexibility.

Best for: Main building entries with access control, healthcare corridors, restricted-access rooms.

Browse electrified locks at American Locksets.

Keypad and Proximity Locks

Keypad and proximity locks replace the physical key with a PIN, a proximity card, or both. Users enter a code or tap a credential to operate the latch. No key required for routine access, and most models run on AA batteries- no hardwiring needed.

The Alarm Lock Trilogy series is the commercial standard here:

• DL2700: 100 user codes, no scheduling, no audit trail. Simple standalone applications.

• DL3200: 2,000 user codes, 150 scheduled events, 40,000-event audit trail. Standard for mid-size facilities.

• DL4100: 500 scheduled events, privacy mode, residency mode, full audit trail. Healthcare and institutional standard.

These locks are ideal anywhere you need to manage who gets in without running network cable to every door.

Best for: Healthcare staff areas, school offices, restricted rooms, rental properties, any space needing credential management without full access control infrastructure.

Browse keypad and proximity locks at American Locksets.

Exit Devices (Panic Bars)

Exit devices- also called panic bars, push bars, or crash bars- are required by code on commercial doors serving 50 or more occupants in assembly, educational, or high-hazard occupancies (IBC Section 1010.1.9). Push the horizontal bar and the door opens, no grip or key required. Operating force must be 15 lbs or less (5 lbs on ADA-accessible egress routes).

Four types cover different door configurations:

Rim devices: Single center latch. Most common for single exterior commercial doors. Von Duprin 98/99 Series, Sargent 8800 Series.

Surface vertical rod (SVR): Three-point latching (center, head, floor). For paired doors without a center mullion. Von Duprin 9827/9927.

Concealed vertical rod (CVR): Same three-point latching but rods run inside the door. Cleaner appearance for architectural applications.

Mortise exit devices: Full mortise lock integrated with push bar function. For primary entries needing key-controlled outside access alongside panic egress.

One important distinction: standard panic hardware can be mechanically dogged (held open). Fire exit hardware- required on fire-rated door assemblies- carries UL 10C listing and cannot use mechanical dogging because fire doors must positively latch on every close.

Best for: All egress doors in commercial occupancies where code requires panic hardware.

Browse exit hardware at American Locksets.

Magnetic Locks (Maglocks)

Magnetic locks use an electromagnet mounted on the door frame and an armature plate on the door. When energized, the magnet holds the door shut with 600–1,500 lbs of force depending on the model. Cut power and the door is immediately free to open.

Maglocks are always fail safe by design- no power, no magnetic hold, door is free. That makes them a natural fit for egress paths, but fire alarm integration is required so the magnet releases automatically during a fire event.

The limitation of maglocks is that they provide holding force only, not a projecting bolt. That makes them better suited for glass and aluminum storefront doors where a mortise prep isn't available, rather than high-security applications where a bolt engagement is needed.

Best for: Aluminum storefront and glass doors, lobby access points, doors where immediate remote release is the priority.

Browse magnetic locks at American Locksets.

Padlocks

Padlocks are portable, self-contained locks with a shackle that passes through a hasp, chain, or staple. Commercial-grade padlocks use hardened steel or boron-carbide shackles and multi-pin cylinders that resist cutting, prying, and picking at a level well above consumer hardware.

They don't get specified on interior commercial doors, but they're the right answer for outdoor gates, storage yards, equipment enclosures, and any application where permanent hardware isn't practical.

Best for: Outdoor gates, job site trailers, storage lockers, equipment yards, utility and infrastructure access points.

Storefront Locks

Storefront locks are narrow-profile locks built for the thin aluminum stile frames of commercial glass storefront doors. Standard commercial mortise and cylindrical locks don't fit these frames- storefront stiles are typically 1-3/4" to 2" wide. Adams Rite is the industry-standard brand here: the MS Series hookbolt and 4500 Series deadlatch cover most storefront applications in North American commercial construction.

Best for: Retail glass entries, office tower lobbies, glass vestibule doors, any aluminum storefront frame where standard door prep doesn't exist.

How Lock Function Codes Work

Every commercial lock ships in a specific function that defines how the inside and outside levers behave. You can't change the function in the field without replacing the lock body- so getting this right before ordering matters.

The most common functions:

The classroom function is the one that trips people up most often- it looks identical to an office lock on the outside but works completely differently during a lockdown drill.

Why American Locksets

American Locksets has supplied commercial door hardware from authorized distribution since 2001. Every lock on this page- mortise, cylindrical, electrified, exit hardware, keypad/prox- is stocked from Schlage, Sargent, Corbin Russwin, BEST, Falcon, and Cal-Royal with current manufacturer warranty.

Call 877-471-4870 before ordering to confirm function code, grade, core prep, and backset. Same-day shipping from multiple US warehouses.

Frequently Asked Questions

What's the difference between a mortise lock and a cylindrical lock? 

A mortise lock fits in a pocket in the door edge and houses everything in a single steel case. A cylindrical lock installs through bored holes in the door face. Mortise is stronger and suits high-traffic institutional doors. Cylindrical is faster to install and works well for interior secondary doors.

When is Grade 1 required?

 On all primary commercial entries, corridors, egress doors, and fire-rated assemblies. Grade 1 is the commercial baseline under ANSI/BHMA standards- not an upgrade.

Can I use a knob lock on a commercial door? 

Not on accessible routes. ADA requires lever hardware on any door on a required accessible route. Knob locks are only permissible on non-accessible utility spaces.

What's the difference between fail safe and fail secure? 

Fail safe unlocks when power is lost- for egress corridors. Fail secure locks when power is lost- for server rooms and pharmacies. Must be specified at order time on most electrified locks.

Where can I buy commercial locks from an authorized dealer?

 American Locksets stocks the complete range at americanlocksets.com. Call 877-471-4870 to confirm specs before ordering.

Published by the American Locksets Hardware Team. Authorized Allegion, Assa Abloy, and dormakaba Dealer, Est. 2001, Monroe, NY.