Introduction
When choosing door knobs for your project, understanding their functions is essential. Different functions meet different needs — for homes, hotels, offices, hospitals, and beyond.
In this guide, we’ll break down the five most common types: Keyed, Passage, Privacy, Dummy and Storeroom. We’ll also show you how each fits into larger door hardware systems like mechanical locks, door handles, hinges, closers, and peepholes.
1. Keyed Function Definition:
A keyed entry knob is a lockable knob that can be operated with a key from the outside and a turn-button from the inside. This is a common choice for entry doors requiring both security and convenience. Some models feature a key mechanism on both sides for extra protection. Ideal for doors that need secure access but must allow safe exit.
Where it’s used:
- Residential front and back doors
- Office entry points
- Doors near windows or glass panels
Features:
- Key access from outside
- Turn-button or push-button lock on inside
- Emergency egress from the inside
- Optional double-cylinder design for added protection
- Often used with deadbolts for increased security
Tip: For doors near glass, use double-keyed knobs or pair a keyed knob with a high-security deadbolt.
2. Passage Function
Definition:
A passage knob is a non-locking knob that includes a latch mechanism to keep the door closed. It can be turned freely from both sides, but it cannot be locked.
Ideal for doors where security isn’t needed but closure is.
Where it’s used:
- Hallways
- Closets
- Children’s playrooms
- Offices with unrestricted access
Features:
- Turns freely from both sides
- Latch holds the door closed without a locking mechanism
- Easy to install
- No key, no privacy lock
Common pairing: Passage knobs often match with tubular latches or standard latch mechanisms. Some customers choose to pair them with magnetic latches for smoother operation and quiet closing.
Learn more about tubular latch mechanisms.
3. Privacy Function
Definition:
A privacy knob is designed for interior doors that require basic locking from one side. It includes a locking mechanism, but does not use a key. It can be unlocked from the outside in case of emergency.
Ideal for private spaces without the need for full security.
Where it’s used:
- Bathrooms
- Bedrooms
- Guest rooms
- Private meeting spaces
Features:
- Lock from inside with a push-button or turn button
- Emergency release from outside using a flat pin or coin
- Provides basic security and privacy
- Available in various finishes: satin nickel, chrome, antique brass, etc.
Optional upgrade: Combine with reinforced privacy lock bodies for a more solid door feel and better durability.
See ANSI lock grading standards here.
4. Dummy Function
Definition:
A dummy knob is a non-functional knob or lever. It does not turn, does not latch, and has no internal mechanism. It is surface-mounted and used for decorative or pull-only purposes.
Perfect for symmetrical design or light-duty use.
Where it’s used:
- Closets
- Pantry doors
- Double doors with one active side
- French doors
Features:
- Surface-mounted with screws
- No latch, no movement
- Used as a handle or decorative piece
- Sold as singles or pairs
Tip: Dummy knobs often match the look of passage or privacy knobs for design consistency across a room or building.
5. Storeroom Function
Definition:
A storeroom knob is designed for secure storage areas. It always remains locked from the outside and can only be opened with a key. Once the key is removed, the knob automatically returns to the locked position.
From the inside, the door always opens freely, ensuring safety for anyone inside the room.
Ideal for securing spaces without trapping people inside.
Where it’s used:
- Utility rooms
- Janitor closets
- Stock rooms
- Electrical or equipment rooms
Features:
- Key unlocks from outside
- No lock/unlock function on the inside knob
- Automatically relocks when closed
- Prevents unauthorized access
- Often includes a UL 3-hour fire rating
Tip: Storeroom knobs are often selected for commercial or institutional use. Always check for fire-rated certification and compatibility with metal or fire doors.
Learn more about UL-rated lock functions here.
Choosing the Right Lock Body
Behind each knob is the lock body — the internal mechanism that makes everything work. At SUZHOU UMAY, we offer a wide range of lock bodies to match your preferred doorknob function:
Lock Body Type | Suited For | Description |
Tubular Lock | Passage & Privacy Doors | Simple, cost-effective, easy to install |
Mortise Lock | Hotels, Offices, High-End Homes | Heavy-duty, key or turn-button privacy |
Deadbolt | Front Doors, Storage Rooms | Extra security, often paired with knob |
Euro Profile Lock | Commercial Spaces | Compatible with cylinder mechanisms |
Explore DIN lock body standards for precision door hardware.
We also provide hinges, peepholes, and door closers to complete your project with a professional finish.
Hardware Finishes and Styles
Function is important, but style matters too. Our knobs and locks come in a variety of finishes and materials to match modern or traditional designs.
- Stainless Steel (304 / 201)
- Zinc Alloy
- Brass
- Matte Black
- Satin Chrome
- Antique Bronze
These finishes are available across knob types and are salt-spray tested for durability.
Why It Matters for Your Business
If you’re a door manufacturer, regional hardware brand, or purchasing manager at a building materials chain — understanding these functions helps you serve your customers better.
Choosing the right door knob function:
- Reduces product return rates
- Increases user satisfaction
- Simplifies inventory planning
Matches specific project needs (residential, commercial, institutional)
Partner With SUZHOU UMAY
At SUZHOU UMAY, we’ve spent over 20 years supplying high-quality door locks, knobs, handles, hinges, peepholes, and closers to clients worldwide.
We support OEM/ODM, large-scale production, and stable supply chains. Our clients include major door factories, hardware importers, and building supply retailers.
Looking for a reliable supplier who knows hardware and understands large client needs?
Let’s talk.
Contact Us to explore our full range of door knob functions and lock systems.
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