Screw Sizes: Understanding Standard Mounting Dimensions

Choosing the right screw size is essential for safely and efficiently mounting objects. The size of the screw will depend on the weight and dimensions of the object being mounted, as well as the type of surface it is being mounted on. For example, when mounting a TV, the length of the screw should be considered to ensure it penetrates the mounting surface and the wallboard of the TV. The weight of the TV is also important, as heavier TVs will require larger screws. Similarly, when mounting a camera on a tripod, the screw thread size should be compatible with the camera type, with larger professional cameras typically requiring a larger screw size.

TV mount screw size

When mounting a TV to a wall, the type of screw you will need depends on the make and model of your TV. The most common screw for securing a TV to a wall bracket is an M8 screw, with other common sizes including M4, M5, and M6. The length of the screw will depend on the depth of your specific TV.

For example, the Vizio E420VL model requires M6 screws that are 20mm in length and have a 1.0mm pitch.

If you are unsure about the type of screw you need, you can refer to your TV's manual or purchase a universal TV to wall bracket screw kit, which comes with a variety of screws, spacers, and washers.

Camera mount screw size

Camera equipment can be confusing, especially when it comes to the various screw sizes. The standard screw size for a camera mount depends on the type of camera and equipment you are using.

The Standard Camera Tripod Screw Thread Sizes

There are two standard camera tripod screw thread sizes: 1/4-20 UNC and 3/8-16 UNC, which are part of the Unified Thread Standard (UTS). The number after the thread size refers to the number of threads per inch. UNC means that these are coarse threads in the Unified Thread Standard (C=Coarse), which is based on the imperial unit of the inch.

The 1/4-inch screw size is for most cameras and some lenses, while the 3/8-inch screw is for larger professional cameras.

Camera Bodies

All camera bodies have a female thread where you can attach the screw from the tripod or the quick-release plate. Most camera bodies have a 1/4-20 camera mount.

Tripod Mounting Plates

The mounting plate is a detachable part of your tripod that attaches to the bottom of the camera. The most common ones are quick-release plates, which can be L-brackets or standard plates. They commonly have a 1/4-20 screw thread, but they may also have a 3/8-16 one or both.

Tripod Heads

Most high-end tripods allow you to buy the head and legs separately. The tripod head has a female screw thread that connects with the screw from the tripod. Tripods built to support heavier equipment will have a 3/8-16 screw, while lighter tripods mostly have a 1/4-20 screw.

Accessories

You can use tripod screw adapters to attach accessories with different screw thread sizes. Adapters are available in various types, such as 1/4" to 3/8" (male to male), 3/8" to 1/4" (male to male), and male to female adapters with different standard screw threads on each side.

History of the Standard

In the late 19th century, the Royal Photographic Society suggested the 1/4-20 and 3/8-16 standards using the British Standard Whitworth (BSW). This was used until the ISO issued an international standard for connecting cameras and tripods, adapting the 1/4-20 and 3/8-16 to the UNC.

Screw types and uses

Screws are a common type of fastener used to adhere different materials together. They are similar in size, shape, and function to nails, but screws have ridges called "threads" that grip the inside of the screw hole. There are many types of screws, each designed for a specific purpose.

The basic parts of a screw include the drive, the screw head, the shank, the tip, and the threads. The drive is the recess in the head of the screw where a screwdriver or driver bit is inserted. The screw head is the top part of the screw, typically circular and wide to prevent the screw from ripping through the material. The shank is the smooth area between the head and the threads. The tip is the end of the screw, and the threads are the ridged part that wraps around the shaft.

• Wood screws are used for basic wood construction and woodwork projects, joining two pieces of wood together. They have coarse threads and a sharp tip that penetrates wooden surfaces. Wood screws are available with either a round head or a flat head.
• Drywall screws are fully threaded screws used for interior projects, such as securing drywall to wooden or metal studs. Coarse-threaded drywall screws are used with wood studs, while fine-threaded screws are for metal studs.
• Deck screws are designed for outdoor construction projects such as decks, fencing, and railing. They are made of corrosion-resistant materials like stainless steel and have a flat head that sits flush with the surface.
• Cement board screws are fully threaded screws that secure backer boards to wall studs or subfloors for tile projects. They have a coating to resist corrosion and can be used with wood, metal, or both.
• Lag screws or lag bolts are used to fasten heavy materials or components that handle large loads. They have hex heads and require a wrench or socket for installation.
• Structural wood screws are similar to wood screws but are much stronger. They have coarse threads and an unthreaded shaft, and they can function like lag screws or bolts depending on building codes.
• Machine screws are fully threaded screws that secure metal components together. They are commonly used in machinery, electronics, appliances, and vehicles.
• Sheet metal screws are designed to fasten sheet metal or softer materials. They have sharp tips to penetrate tough metal surfaces and fine threads for superior grip. They come in a range of sizes and head styles, including flat, rounded, and hex heads.
• Concrete screws or masonry screws are used for fastening concrete, brick, or other masonry materials. They require a pilot hole to be drilled before insertion and are typically recognized by their two different thread patterns.
• Multi-material screws have features that allow them to be used with various types of materials, such as wood, sheet metal, drywall, masonry, and plastic.
• Security screws are standard screws with unique heads that make them more difficult to remove without the appropriate tools. They are often used in public places to deter vandalism, theft, and tampering.
• Camera tripod screws have two standard sizes: 1/4-20 UNC and 3/8-16 UNC, which are part of the Unified Thread Standard (UTS). The 1/4-inch size is for most cameras and some lenses, while the 3/8-inch size is for larger professional cameras.
• TV mount screws typically use M4 x 12mm, M6 x 12mm, or M8 x 16mm screws. The right size depends on the VESA pattern of the TV, which refers to the distance between the mounting holes.

Screw length

When mounting a TV, for instance, the screw length should be sufficient to penetrate the mounting surface and the wall board by at least 1/2". Typically, screws ranging from 3/4" to 1 1/2" in length are used for this purpose. However, if you have a heavier TV, longer screws may be necessary to provide adequate support. It is crucial to use screws that are not too short, as they may cause the TV to come loose and fall. On the other hand, screws that are too long can strip the holes in the TV, resulting in damage.

The VESA pattern, which refers to the standardised arrangement of four mounting holes on the back of televisions, is an important consideration when determining screw length for TV mounts. By measuring the distance between these holes, typically in millimetres, you can select screws that are long enough to securely fasten the TV to the mount. The VESA pattern also helps in determining the appropriate screw size, as certain TV models may require specific screw types or sizes.

For camera mounts, the thread size is a critical factor. The two standard thread sizes for camera tripod screw threads are 1/4-20 UNC and 3/8-16 UNC, which are part of the Unified Thread Standard (UTS). The 1/4-inch screw size is commonly used for cameras and some lenses, while the 3/8-inch screw size is designed for larger professional cameras. The length of the screw bolt on a tripod's quick-release plate can vary, with some being short and others quite long.

When selecting screws for any application, it is essential to consider the weight of the object being mounted and the thickness of the mounting surface. Longer screws are typically required for heavier objects to ensure they can withstand the load. Additionally, the type of wall or surface being screwed into should be considered, as certain surfaces, such as brick or concrete, may require special screw anchors for secure fastening.

Screw diameter

The diameter of a screw is the outside distance measurement of its threads. The larger the number associated with a screw, the larger its diameter. For instance, a #10 screw is larger than a #8 screw. The diameter is usually measured in inches or millimetres. For example, a 5/32-inch screw diameter is equivalent to 0.15625 inches or 3.96875 millimetres.

For TV mounts, the most common screw diameters used are M4, M6, and M8. The M4 x 12mm screws are used to fasten TV mounts to the back of televisions, while the M6 x 12mm screws are used to mount the TV to the mount. The M8 x 16mm screws are used to secure the TV to the mount, providing a snug fit without overtightening.

Camera tripods typically have two screw thread sizes: 1/4-20 UNC and 3/8-16 UNC. The 1/4-inch screw size is commonly used for cameras and some lenses, while the 3/8-inch screw size is designed for larger professional cameras. The UNC designation refers to the Unified Thread Standard, indicating coarse threads with a 60-degree thread profile.

It's important to note that screw diameter is just one aspect of screw size. The length of the screw is also crucial, and the required length will depend on the specific application.

Frequently asked questions