Choosing The Right Drywall Screw: Size Table

Drywall screws are the standard fasteners for securing drywall to walls or ceilings. They are favoured for their strong tacking power, ease of use, and economy. The length of a drywall screw varies depending on where it will be used. The standard drywall size is 1/2 inch thick, but it can be thicker or thinner. The thickness of the drywall will determine the length of the screw needed. For instance, for 1/2-inch drywall, use 1-1/4-inch or 1-5/8-inch drywall screws. For 5/8-inch drywall, use 1-5/8-inch or 2-inch drywall screws. Drywall screw threads are classified into two categories: fine and coarse, each serving a different purpose. Coarse-thread drywall screws are best suited for installing most wood studs and drywall, while fine-thread drywall screws are ideal for attaching drywall to metal studs.

Drywall screw length

For thicker drywall, such as 5/8-inch, which is often used for ceilings or in commercial buildings, longer screws like 1 5/8-inch or 2-inch are commonly recommended. Again, if you're dealing with metal studs, you might want to opt for a slightly shorter screw, such as 1 1/4-inch.

There are also thinner drywall options, such as 3/8-inch or 1/4-inch, which generally require shorter screws. A 1-inch screw is usually sufficient for securing this type of drywall to either wood or metal studs.

It's important to note that the length of the screw should allow for at least 1/2 inch of penetration into the stud. Additionally, the type of thread on the screw is crucial, with coarse-threaded screws being ideal for wooden studs and fine-threaded screws for metal studs.

When in doubt, always refer to the manufacturer's guidelines to ensure you're using the correct length and type of screw for your specific application.

Drywall screw threads

When it comes to specific products, Grip-Rite offers a range of both coarse and fine-thread drywall screws. For example, their #6 x 1-5/8" Phillips Bugle Head Fine Thread Drywall Screw is designed for attaching drywall to metal studs, providing a strong hold with its fine threads and easy penetration with its sharp, self-piercing point. It also features a countersunk bugle head that creates a clean, finished look.

Another option from Grip-Rite is their #6 x 2" Phillips Bugle Head Fine Thread Drywall Screw, which is also suitable for interior drywall applications. These screws are made from high-strength steel, providing durability and a strong hold. For attaching drywall to wood, Grip-Rite's coarse-thread options, such as their #6 x 1-1/4" or #6 x 1-5/8" screws, would be a better choice as they provide greater holding power.

PROFFERED also offers drywall screws with fine threads, specifically designed for attaching drywall or gypsum board to light gauge steel studs. These screws feature a reduced Phillips drive, which provides a secure fit and reduces wobble during installation.

Drywall screw gauges

The most commonly used drywall screw gauges are #6 and #8. A #6 gauge is typically used for almost all drywall installation, but in some specific circumstances, a thicker drywall screw is needed, and a #8 gauge can be used.

The gauge number is usually listed after the length of the screw on product labels. For example, a 1-5/8-inch long screw with a #6 gauge would be written as "1-5/8 inch x 6".

It's important to select the correct size of drywall screw for your project. While there is a wide variety of screw sizes available, only a handful are suitable for use with drywall. The standard drywall thickness is 1/2 inch, and the recommended screw length for this is 1-1/4 inches to 1-5/8 inches.

For thicker drywall measuring 5/8 inches, you should use screws ranging from 1-5/8 inches to 2 inches in length. These longer screws are also recommended when installing thicker drywall on ceilings to prevent sagging and cope with the additional weight.

For thinner drywall measuring 1/4 inch, you can use shorter screws ranging from 1 inch to 1-1/4 inches in length.

Drywall screw coatings

Phosphate Coating:

Phosphate-coated drywall screws are typically black in appearance. This coating helps to increase the screw's resistance to rust and corrosion. It is important to note that phosphate-coated screws are not recommended for use in wet or exterior environments, as they can still be susceptible to rusting over time. However, they are a good choice for indoor projects where moisture is not a significant concern.

Zinc Coating:

Zinc-coated drywall screws offer some corrosion resistance. However, if they begin to rust, they can damage the surrounding plaster and wall finish. Therefore, it is crucial to avoid using zinc-coated screws in areas with high moisture levels.

Vinyl Coating:

Drywall screws with a thin vinyl coating are highly corrosion-resistant. The slippery nature of the vinyl coating also makes these screws easier to drive into the drywall. This type of coating is an excellent choice for projects where corrosion resistance is a top priority.

Galvanized Steel Coating:

For maximum corrosion resistance, especially in outdoor applications, consider using drywall screws coated with galvanized steel. This coating provides superior protection against rust and corrosion, making it suitable for use in damp or humid environments.

Stainless Steel:

Stainless steel drywall screws are another option for moisture-prone areas. They are inherently resistant to rust and corrosion, making them a durable choice for both indoor and outdoor projects.

To summarize, when selecting drywall screws, consider the environment in which they will be used. For indoor projects, phosphate-coated or black drywall screws are suitable, while for damp or outdoor environments, prioritize stainless steel, galvanized steel, or coated screws designed for such conditions. Proper ventilation and moisture control also play a role in preventing rust formation. Additionally, ensure correct installation and consider using appropriate sealants for further protection against moisture intrusion.

Drywall screw features

Drywall screws are the standard fastener for securing drywall to walls or ceilings. They are favoured for their strong tacking power, ease of use, and economy. When choosing between drywall screws and nails, it is recommended to opt for screws, especially when working with metal studs or frames, or on ceiling installations.

Bugle Head: The cone-like shape of the screw head is called a bugle head. This shape helps the screw stay in place without tearing through the outer paper layer of the drywall. The curved head creases the top paper layer rather than sinking into the wood.

Sharp Point: Some drywall screws have sharp points that make it easier to stab the screw into the drywall and get it started.

Drill-driver: For most drywall screws, a #2 Phillips head drill-driver bit is used. While construction screws are increasingly adopting Torx, square, and other head shapes, most drywall screws continue to use the Phillips head.

Coatings: Drywall screws are often coated with phosphate or zinc. Phosphate coatings, especially in black or grey, offer better protection against rust and corrosion. A thin vinyl coating on some drywall screws makes them highly corrosion-resistant. These vinyl-coated screws are also easier to draw in due to their slippery shanks.

Thread Types: Drywall screw threads are typically classified as either fine or coarse. Coarse-thread screws, also known as W-type, are ideal for screwing drywall into wood studs. The wide threads mesh well with the wood grain and provide a strong grip. However, they can cause metal burrs that may embed in your fingertips, so it is recommended to wear gloves when working with these screws. Fine-thread screws, also known as S-type, are better suited for attaching drywall to metal studs. They are self-threading and grip metal surfaces effectively without chewing through it.

Screw Gauge: The diameter of a drywall screw is referred to as its gauge. The most commonly used gauges for drywall screws are #6 and #8. As the gauge number increases, so does the diameter of the screw. Thus, a #6 drywall screw is thinner than a #8 screw.

Length: The length of a drywall screw depends on the thickness of the drywall and the type of stud it will be attached to. For standard 1/2-inch thick drywall, screws ranging from 1-1/4-inch to 1-5/8-inch are typically used. For thicker drywall measuring 5/8-inch, longer screws ranging from 1-5/8-inch to 2-inch are required.

Screw Spacing: While there is no uniform rule for drywall screw spacing, a general guideline is to use 32 screws per drywall panel. On the margins of a wall, screws should be spaced 8 inches apart, and throughout the rest of the wall, they should be 16 inches apart.

Frequently asked questions