Parts of a Door: A Comprehensive Guide – All You Need to Know
If you’re in the market for a new door or need to repair an existing one, understanding the terminology and basic parts of a door can be incredibly helpful. This glossary of door parts will break down all the technical terms and components of a door, making it easier to communicate with contractors and dealers to choose the right door for your project.
This post will cover everything from the door frame and jamb to the lockset and handle, including components such as the sill, threshold, glazing, sidelights, casing, weather-stripping, and more. By the end of this article, you’ll have a comprehensive understanding of the anatomy of a door and the function of each part.
Key Takeaways
- Understanding the basic parts of a door can make it easier to communicate with contractors and dealers when shopping for a new door or repairing an existing one.
- This glossary will cover everything from the door frame and jamb to the lockset and handle, including components such as the sill, threshold, glazing, sidelights, casing, weather-stripping, and more.
- By the end of this article, readers will have a comprehensive understanding of the anatomy of a door and the function of each part.
Door Frame
A door frame is made up of side jambs, head jambs, and mulls. Residential door frames are commonly constructed from wood but can also be made from aluminum, fiberglass, or composite materials. Door frames can be purchased primed and ready to paint or ordered with a factory finish in various colors.
Head Jamb
The head jamb is the top horizontal section of a door or window frame. It is an essential component of the frame that holds the door in place. The head jamb is crucial in providing structural support and stability to the door. It is also responsible for bearing the weight of the door and distributing it evenly to the side jambs. The head jamb is usually made of wood or metal and is designed to fit snugly into the frame. It is imperative that the head jamb is installed correctly to ensure that the door functions properly.
Door Jamb Versus Door Frame
A door jamb is a vertical component of a door frame that holds the entire structure in place. Two side jambs and a head jamb make up the door frame. The side jambs have to hold the latch and hinges, while the head jamb connects the side jambs horizontally. Together, the jambs and mullion comprise the door frame.
Mullion (Mull)
A mullion, also known as a mull, is a vertical or horizontal element that separates two or more window units or a door and window unit. It is the seam between the frames of two units that have been joined together. A door jamb can be joined to a window/sidelight jamb to create a mull. A mull casing, which is a piece of trim, is typically used to hide the seam.
Sill
Sills are the bottom part of a door frame that gets sealed and fastened to the floor. They are found only on exterior doors leading to the outdoors or garages. Proper installation of a sill is important to prevent water, air, and other outside elements from entering the home. It is crucial to prepare the floor for a door sill to ensure a tight and lasting seal.
Threshold
A threshold is a protective cover that sits on the sill of a door. It is designed to be sloped towards the outside to prevent water from entering the building. Thresholds are made of durable materials like metal or fiberglass to withstand foot traffic.
Glazing
Glazing is a term used to describe the glass in a door or window. Newer exterior doors are made up of at least two layers of glass, sometimes three, with inert gas, usually argon, injected between the layers to provide additional insulation. Nearly invisible coatings are added to the glass to help manage the amount of light and heat conducted through a windowpane or reflected away from it. Glazing can be enhanced with tints and laminations to add privacy, provide decorative options, and increase strength. It is also possible to add grilles or muntins to the glass panels for a more decorative look.
Sidelights
Sidelights are narrow windows that are installed on one or both sides of a door. They are designed to allow more natural light into the entryway, enhance views, and create a more welcoming entry point experience. Sidelights are typically made of glass and can be fixed or operable. They come in different shapes, sizes, and styles to match the door and complement the overall design of the house. Sidelights are commonly installed on exterior doors, but they can also be used on interior doors to enhance the visual appeal of the room.
Casing
Casing trim is used to cover gaps between a door or window frame and the interior wall surface. It can be made of wood, MDF, or other materials. Casing can be plain or decorative, and it can also be used to hold the door or window in place. Molding is another option for adding decorative elements to the casing.
Brick Mould
Brick mould is a type of exterior casing trim that is installed on a door or window to bridge the gap between the frame and the exterior wall surface. It is thicker than most interior casing trim profiles and acts as a buffer between the door or window and the brick or other cladding surrounding it. Brick mould can be made of different materials such as wood, aluminum, PVC, fiberglass, or composite materials. It also serves as the attachment point for screen doors or storm doors.
Weather-stripping
Weather-stripping is a resilient, flexible material used to seal gaps between a door frame and a closed-door panel. Common materials for weather-stripping include silicone, rubber, and foam. It is typically used on exterior doors to prevent drafts and improve energy efficiency.
Door Sweep
A door sweep is a weather-stripping installed on the bottom of a door panel that creates a weather-resistant barrier between the door panel and sill. It helps prevent drafts, energy loss, and pests from entering the room. Door sweeps come in different types, including strip, bristle, and under-door, and are easy to install and replace. The most common type of door sweep has an aluminum strip that attaches to the face of the door, with a thin vinyl strip insert acting as the sweep. It is effective for most needs and inexpensive.
Astragal
An astragal is a vertical strip that covers the seam between two door panels in an exterior double door arrangement. It is fitted with weather-stripping to prevent wind and water from entering the house.
Transom
A transom is a narrow window situated above a door or window. It is typically non-operational, but if it does open, it is usually hinged at the top like an awning window. The traditional use of muntin bars has been replaced with simulated divided lite bars (SDL) that rest on the surface of the glass because large panes of glass are now stronger, less expensive to manufacture, and more energy-efficient.
Grilles
Grilles are bars that give the appearance of divided lites. They can be removed for easy glass cleaning. Grilles-Between-the-Glass (GBG) are bars that are installed permanently between the glass panes for easy cleaning and low maintenance.
Muntin Bars
Muntin bars are strips of wood or metal that separate and hold panes of glass in a window. They were commonly used in Western architecture to create large expanses of glass from smaller individual panes. This was necessary because larger panes of glass were fragile and expensive to create prior to the middle of the 19th century.
Panel
A door panel, also known as a slab, is the part of the door that swings open and closed. It can be made up of smaller panels, which are positioned between the stiles, rails, and mullions. In a pair of doors, the fixed panel is the panel that does not open or close.
Rail
Rails are the narrow horizontal segments that form the basic structural backbone of a door panel. They are located at the top, bottom, and mid-section of the door. The mid-rail spans the width of the door and provides stability to the door panel.
Stile
A stile is a narrow vertical component on either side of a door panel. There are two panels on both vertical edges of a door frame; the lock stile and the hinge stile.
Mullion
A mullion is a vertical component that separates two panels located in the middle of the door between the rails. It is similar in appearance to a stile.
Stop Moulding
Stop moulding is a type of moulding that is attached to the door frame. It is used to align the door panel within the frame and prevent the panel from swinging right through the opening. Stop moulding can be both decorative and functional, and it comes in various materials such as wood, vinyl, and PVC composite. Here are some key features of stop moulding:
- Prevents door panel from swinging through the opening
- Aligns the door panel within the frame
- Can be decorative and functional
- Available in various materials such as wood, vinyl, and PVC composite
Stop moulding is an essential component of any door frame, and it helps to ensure that the door functions properly and looks great. Whether you’re renovating your home or building a new one, choosing the right stop moulding can make all the difference.
Hinge
A hinge is a hardware component that allows doors to swing open and closed. Standard doors have three hinges, while larger doors may have four or more. The color and finish of the hinge typically match the lockset. Most hinges consist of three basic parts: leafs, knuckles, and a pin. There are various types of hinges, including pivot hinges and concealed hinges.
Bore Hole
A bore hole is a hole that is drilled into a door panel to accommodate a lockset. It is typically pre-drilled, although some doors may not have an existing bore hole. The bore hole is where the door handle or lockset is installed.
Here are some key points to keep in mind about bore holes:
- The size of the bore hole will depend on the type of lockset being installed.
- Bore holes are typically located on the face of the door panel, near the center.
- Bore holes can be drilled using a specialized drill bit designed for this purpose.
- It is important to ensure that the bore hole is centered and properly aligned to avoid any issues with the lockset installation.
Overall, bore holes are a critical component of a door’s hardware, as they allow for the installation of locksets that provide security and access control.
Lockset
A lockset, also known as a handleset or hardware, is a collection of components that allow a door to latch and lock. It includes handles, locks, latches, and strike plates. The cylinder is the locking mechanism that is inserted into the lockset.
Handle
A handle, knob, or lever is the component of door hardware that is used to unlatch the door panel and pull it open or push it closed. There are many styles and finishes to choose from. There are three types of door handles:
Entry Handles
Entry handles are operated with a key cylinder on the exterior side of the door and a push or turn lock button on the interior. These handles are perfect for front doors and other doors that require security.
| Features | Description |
|---|---|
| Locking Mechanism | Yes |
| Key Cylinder | Yes |
| Push or Turn Lock Button | Yes |
| Suitable For | Front doors and other doors that require security |
Bed/Bath Handles
Bed/bath handles have a push or turn lock button on the inside but not on the other. These handles are suitable for bedrooms and bathrooms, where privacy is important.
| Features | Description |
|---|---|
| Locking Mechanism | Yes |
| Key Cylinder | No |
| Push or Turn Lock Button | Yes |
| Suitable For | Bedrooms and bathrooms |
Passage Handles
Passage handles have no locking mechanism. These handles are perfect for closets, hallways, and other doors that do not require security.
| Features | Description |
|---|---|
| Locking Mechanism | No |
| Key Cylinder | No |
| Push or Turn Lock Button | No |
| Suitable For | Closets, hallways, and other doors that do not require security |
Latch
A latch is a shaft that protrudes from the edge of a door panel and into the door frame, securing the panel in place. When the handle is turned, the latch retracts, allowing the door to be opened.
Deadbolt
A deadbolt is a type of lock that provides additional security to the door. It is a shaft that protrudes from the edge of the door panel and into the door frame, securing the panel in place. Deadbolts are usually separate from the handle assembly, which means that a door with a deadbolt needs an additional bore hole. Residential interior doors typically do not have deadbolts, and not all exterior doors have them either. Multi-point locking hardware systems provide even more protection than a latch and deadbolt combination. New home automation systems are also available to enhance security.
Thumb Turn
A thumb turn is a small knob or lever that is usually located on the inside of a door. It is used to operate a deadbolt lock by turning it. The thumb turn is typically located near the bottom of the lock cylinder, and it is often shaped like a small knob or lever.
The thumb turn is an important part of a deadbolt lock, as it allows the lock to be easily engaged and disengaged from the inside of a house. This is especially important in case of an emergency, as it allows the occupants of a house to quickly and easily exit in the event of a fire or other emergency.
Overall, the thumb turn is a simple but essential part of a deadbolt lock, and it is an important consideration when choosing a lock for a home or other property.
Mortise Plates
Mortise plates are long, flat metal plates that are mortised into the door panel. They add strength to latches, deadbolts, and the door panel, which helps prevent a forced entry. The door latch and deadbolt pass through the mortise plate to secure the door to a strike plate in the door frame.
Some key points to note about mortise plates include:
- They are made of metal.
- They are long and flat.
- They are mortised into the door panel.
- They add strength to latches, deadbolts, and the door panel.
- They help prevent forced entry.
- The door latch and deadbolt pass through the mortise plate to secure the door to a strike plate in the door frame.
Mortise plates are an important part of a door’s security system, and they play a crucial role in keeping a home or building safe.
Strike Plates
Strike plates are an essential component of a door’s locking system. They are metal plates affixed to the doorjamb and have a hole or holes that accommodate the lock bolt. Strike plates add strength to door frames, which helps prevent a forced entry. They also protect the doorjamb and add security to the opening.
In addition to reinforcing the door locking system, strike plates come in various shapes and sizes to fit the specific type of lock and door. They can be made from different materials, including stainless steel, brass, and aluminum. It’s important to choose a strike plate that matches the lock and door to ensure proper function and security.
When installing a strike plate, it’s crucial to ensure that it’s properly aligned with the lock bolt. Misalignment can cause the bolt to miss the hole, making it easier for intruders to force the door open. Therefore, it’s recommended to hire a professional locksmith to install a strike plate to ensure proper alignment and security.
Overall, strike plates are an essential component of a door’s locking system, and choosing the right one can significantly enhance the door’s security.
Escutcheon
Escutcheons are decorative plates that surround handles, thumb turns, and key cylinders. They serve a dual purpose of protecting the surface of the door panels from nicks and scratches while also adding a touch of elegance to the door. They are usually made of brass, bronze, or stainless steel and come in different shapes and sizes. Marvin has a team of experts who work with architects, builders, and homeowners to help them find the best Marvin products for their next project. Connect with a dealer in your area to visit a showroom and discover which Marvin products will work best for you.
Frequently Asked Questions
A door lock mechanism typically consists of several components that work together to secure the door. These components include the lockset, which includes the lock cylinder, latch, and deadbolt. The lockset is attached to the door with screws and is operated by a key or thumb turn. Other components of the lock mechanism may include strike plates, which are attached to the door frame and receive the latch or deadbolt, and a door closer, which automatically closes the door after it is opened.
A door frame is typically constructed from wood or metal and consists of several main parts. These parts include the head jamb, which is the horizontal piece at the top of the frame, the side jambs, which are the vertical pieces on either side of the frame, and the sill, which is the horizontal piece at the bottom of the frame. The frame may also include mullions, which are vertical pieces that divide the frame into smaller sections, and casing, which is decorative trim that covers the gap between the frame and the wall.
A door hinge assembly typically consists of three main parts: the hinge leaves, the hinge pin, and the hinge knuckles. The hinge leaves are the flat metal plates that are attached to the door and the door frame, while the hinge pin is the cylindrical rod that connects the hinge leaves. The hinge knuckles are the rounded portions of the hinge leaves that rotate around the hinge pin.
A door handle typically consists of several parts, including the handle, the latch, the spindle, and the rosette. The handle is the part that is grasped and turned to open the door, while the latch is the mechanism that holds the door closed. The spindle is the metal rod that connects the handle to the latch, and the rosette is the decorative plate that covers the hole in the door where the handle is installed.
The threshold of an exterior door is the part of the frame that extends beyond the door and forms the bottom of the doorway. It typically consists of a metal or wood plate that is attached to the floor and the bottom of the door frame. The threshold may also include weatherstripping or a sweep to help prevent drafts and moisture from entering the building.
A door jamb is the vertical part of the door frame that supports the weight of the door and provides a surface for the hinges to attach to. It typically consists of a piece of wood or metal that is attached to the wall and the head jamb of the frame. The jamb may also include a stop, which is a thin strip of wood or metal that prevents the door from swinging too far into the room.
Hello, I’m Keith Jones. I’m the author and head of content here of door and window guide. I’ve been in the window and door industry for over 10 years in the UK and North America. I’ve had quite a few roles during my career mainly in Worldwide sales. I’m now semi retired so I thought I’d put my knowledge to good use educating people about all they might need to know about door and window related topics.
