Sheetrock screws, also known as drywall screws, are the industry standard for fastening drywall sheets to ceiling joists or wall studs.
Between the threads, lengths, numbers, gauges, heads, and points, deciphering what type of drywall screws to use may seem impossible.
Basics of Drywall and Sheetrock Screws
In reality, the wide array of sheetrock screws available for purchase can be narrowed down to a few options that cover most drywall screw uses.
A basic understanding of the main features and specific purposes of drywall screws will provide enough know-how to get started on any drywall-fastening project.
These main features are the drywall screw length, drywall screw threads, and drywall screw gauges.
Sheetrock Screw Length
The first factor to consider when purchasing sheetrock screws is the screw length. The correct drywall screw length depends on the type of material being used.
For general construction, screws can be up to 8 inches long for use in thicker materials. Since drywall is so thin, 8-inch screws won’t be used, but the thickness of the drywall still determines drywall screw length. The rule of thumb for screw length is:
For ¼-inch drywall, use 1-inch to 1 ¼-inch sheetrock screws.
For ½-inch drywall, use 1 ¼-inch to 1 ⅝-inch sheetrock screws.
For ⅝-inch drywall, use 1 ⅝-inch to 2-inch sheetrock screws.
Different thicknesses of drywall panels serve different purposes, so purchase a longer drywall screw in lengths appropriate for your project.
The most common drywall thickness for a residential jobsite is ½-inch, which can be used for most purposes.
⅝-inch drywall is used for increased soundproofing and for meeting certain fire codes in commercial buildings. And ⅝-inch thick type-x drywall prevents fire spread more effectively than 1/2″ drywall.
Thicker drywall requires different sheetrock screws, so be sure you know the drywall thickness prior to buying your screws.
¼-inch drywall is thin and flexible and therefore often used to cover curved areas like dish-shaped ceilings. Another option is to use drywall nails, but of course, you would need to be sure these are allowable for your application.
Sheetrock Screw Threads
Drywall screw threads can be broken down into two types, each of which serves different purposes: coarse and fine.
Coarse Thread Sheetrock Screws
Coarse thread drywall screws, or w-type screws, are best used when fastening drywall to wood studs. The wider, deeper threads get a better grip on the wood grain, allowing for a more secure pull on the drywall against the wood stud.
However, since the coarse thread sharp screws have wider threads, the larger burrs can easily cut fingers so it’s best to wear gloves when working with coarse thread wood screws and drywall screws.
Fine Thread Sheetrock Screws
Fine thread Phillips drywall screws are used primarily when working with metal studs.
These screws are self-threading, meaning the sharp threads surrounding the screw are able to efficiently cut their own secure path into the material (in this case, metal or steel studs).
Fine thread sheetrock drywall screws, or s-type screws, are used for metal studs as opposed to coarse-threaded screws. The coarser threads are less effective for drilling into metal, oftentimes chewing it up, resulting in a weaker hold.
On the other hand, finer threaded screws mean less surface area to grip wood grains. So coarse threads work better when working with wood studs to account for the wood grain.
Drywall Screw Gauges
The third main factor when determining which type of screw to purchase is the drywall screw gauge.
Gauge is a fancy word that simply refers to the diameter of the sheetrock screw.
For the majority of applications, #6 or #8 drywall screws are going to be used. It’s important to keep in mind that, unlike some other construction materials, drywall screws get thicker when the numbers get higher. Therefore, a #8 drywall screw is thicker than a #6.
The actual diameters of the screws are:
- 0.138 inches for #6 screws
- 0.164 inches for #8 screws
Different gauges are used for different-sized studs. In the case of drywall screws, it should be fine to use either #6 or #8 screws in most applications.
When purchasing sheetrock screws at your local home improvement store, the gauge is often listed as a number after the screw length. For instance, a 1 ¼-inch screws and #8 gauge items are listed as “1 ¼-inch x 8.”
Stainless Steel Drywall Screws
Another option for drywall and sheetrock screws is to use stainless steel. These screws are much tougher because of their high tensile strength and high corrosion resistance.
Stainless steel sheetrock screws also have high creep rupture strength because of the added chromium and nickel to the allow. This additional strength might make stainless steel sheetrock screws a better choice.
Another option is the yellow zinc screw, which adds a yellow chromate layer to prevent corroding.
There is also black oxide drywall and sheetrock screws, which have a black phosphate coating that keeps the wet drywall compound from rusting the screw head.
Other Drywall Screw Terminology
The above three factors are the main pieces of terminology that you’d likely run into when learning about sheetrock screws.
Delving into the terminology and features of drywall fastening can be overwhelming at first, but as shown above, understanding drywall screws isn’t too complicated.
However, you may have seen some other terms like “sharp point” and “bugle head” which are just as easy to understand.
Bugle Head Sheetrock Screws
Drywall screws called “bugle screws” or “Phillips bugle head screws” refer to the shape of the screw’s head which is specifically designed for drywall application.
Bugle head drywall screws distribute stress over a much wider area than flat-head screws are able to by creating its own countersunk hole when screwed in.
Basically, the bugle head is great at securing the screw in place without tearing up the gypsum board paper and is great at being screwed flush with the material itself.
A sharp point drywall screw is a favorite for its ability to self-tap. “Tapping” or a self-drilling drywall screw refers to initially piercing a material, like a wood stud, to give a screw a starting point to drill into.
Sharp point and self-tapping, or self-drilling screws have sharper points, making it much easier to stab into the drywall and get started for a quicker and more secure connection.
Phillips Bugle Head Sheetrock Screw
The Phillips drive screw was originally patented in 1932. John P. Thompson created the design, but failed to interest manufacturers to put his unique screw head into production. He sold his screw head design to Henry F. Phillips, who formed the Phillips Screw Company.
It was a breakthrough in screw head design. A high cam out potential much greater than typical slotted screws made the Phillips bugle head drywall screw perfect for sheetrock, and many other applications.
Some criticize the Phillips head design for its tendency to cam out at low torque compared to other slotted heads. But this might be the best feature of the Phillips head screw by not allowing installers to overtighten the fasteners.
When dealing with a sagging ceiling, a Grip-Rite perforated ceiling washer can be added to the drywall screw for superior holding strength.
Square Drive Screw Head
The square drive screw head was designed when you need a little more “cam out” resistance, where more tightening is needed than a Phillips head screw. Much like the hex head screw, the square drive screw head allows for much greater torque.
Square drive screws are often used as connectors in furniture and other hardwoods but can be used in drywall applications when necessary.
Truss Head Screws
Another common screw head is the truss head. The oversized dome-shaped, or mushroom-shaped screw head protrudes out of the surface where they are driven. Similar to the pan head screw, the Truss head is not desirable for drywall because of the protruding head.
Using Sheetrock Screws
With a basic understanding of the features of drywall screws locked down, the struggle now is understanding what type of drywall screws are used and how many screws are needed for use.
The majority of drywall is sold in 4×8, 4×10, or 4×12 foot panels or sheets which are then secured into wooden or metal studs. Wall studs in homes are usually set 12 to 16-inches apart, so for securing a 4×8 drywall sheet against wall studs, you’d need on average 28 screws.
You will always want to refer to your local building code for proper screw patterns and requirements, along with the project’s specifications.
How Many Drywall Screws to Purchase
Because you need a specific amount of screws to safely and securely fasten drywall to studs, purchasing the correct amount of screws is key. However, it can be frustrating to figure out how many drywall screws to buy since they are often sold by the pound.
Many manufacturers, such as Grip-Rite, now sell small boxes of drywall screws for as little as $5.
When purchasing by the pound, the exact number of screws contained is never explicitly said, but there are decent estimates out there:
- For 1 ⅝-inch coarse thread #6 screws, there are about 200 screws per pound.
- For 1 ¼-inch coarse thread #6 screws, there are about 238 screws per pound.
A general rule of thumb is that screws get heavier the longer they are and the higher gauge they have. Longer, higher gauge screws have fewer screws per pound, so make sure you get enough drywall screws.
What Kind of Drywall Screws to Use
Different types of sheetrock screws are better utilized in different places. As noted above, coarse-thread screws are best used when working with wooden studs. Fine thread drywall screws work best with light metal studs.
Depending on the type of project, either ½-inch drywall or 5/8″ drywall sheets are used so 1 ¼ or 1 ⅝-inch sheetrock screws should be used. These lengths can safely and securely tap through ½-inch or 5/8″ thick drywall with plenty of room to secure themselves inside a wall stud.
The longer the screw or fastener, the more secure the hold, but the harder it is to drive into the wall. The 1 ⅝-inch sheetrock screw may be a difficult screw to embed since over an inch remains after going through the initial ½-inch of drywall.
The last ¼-inch to ⅛-inch of a drive is critical since the head of the drywall screw needs to crease the drywall paper and embed itself flush.
The shorter the drywall screw, the easier it is to align this final drive. But if you drive the screw into the drywall too deep, it will fail to stay securely fastened to the wall.
Cement Board Screws
Tile backer cement board requires special screws that resist corrosion. The alkali levels in certain cement board will corrode typical screws.
Cement board screws also include small grooves under the screw head that dig into cement board for increased holding strength.
When To Use and Not Use Drywall Screws
Drywall screws are mainly used when screwing sheets of drywall into wall studs. In this setting, sheetrock screws have become the primary fastener. However, drywall screws have a narrow range of functionality and should only be used for certain projects.
Drywall screws work great with softwood studs, and coarse threads grant great grip to the wood grain. Drywall screws can be used for lighter building projects like building cabinets, so long as safety is not a big factor.
Safety being a factor is critically important because drywall screws are relatively brittle compared to other types of construction screws. While other regular screws and nails tend to bend, drywall screws are liable to snap.
Drywall & Sheetrock Screws
The heads of drywall screws are especially prone to this. While it’s possible to extract bent nails or screws, there’s no way to remove a snapped-off drywall screw shaft from wood boards without pliers, or cutting the screw.
For this reason, drywall screws should never be used for heavy or even moderate building structures. They should not be exposed to the elements like water or snow, critically never to be used when building outdoor projects like decks or fences.
You will want to use a specifically designed deck screw or fence screw for those tasks. Don’t use drywall screws for handrails or stairs as these are weight-bearing functions for which sheetrock screws are not designed.
Additional Resources –
Current Drywall Screw Pricing – Home Depot
Close-Up View of the Grabber Phillips Bugle Head Products – Grabber
Shear Values for Drywall Screws – Chart & Technical Data (Gypsum Association)
Feature product – The Hilti Drywall Screw Drill – AWCI.org