Different Types of Screws and Their Uses
Understanding Screw Anatomy
A screw is a common fastener that features a head, a shank, and threads. The shank of the screw can vary in diameter and length. The shank will feature spiraling ridges called threads on part or all of the shank. At the top of the shank is a larger portion that can be flat or domed, called the head of the screw.
Screw Head Types
Screw heads come in all shapes and sizes. Standard slotted head or flat-head screws use a flat-head screwdriver. The cross-shaped indention or star-head screw is best suited to a Phillips screwdriver. A square-head screw requires a Robertson screwdriver. Each screw head type comes in different sizes, so be sure you have the right screwdriver for the job before you begin.
Common Types of Screws
Most construction projects require one of the following five types of screws. The screw packaging and online product descriptions provide all the detailed information you need to ensure you're purchasing the right screw for your specific project.
Wood Screws
When you're joining two or more pieces of wood, wood screws make the ideal choice. These screws feature a smooth shank supporting coarse threads designed to really grip the wood securely. When you're determining what length screw to purchase, take the full width of the first piece of wood and 2/3 of the width of the lowest board and add those lengths together.
Deck Screws
Decks are subject to exposure to the element and as such, it's essential you install them using the correct type of screw. Deck screws feature a self-tapping design that makes them easy to drive in without pre-drilling a pilot hole. They are designed to countersink into the wood so you don't catch your feet on screw heads and boast a corrosion-resistant construction. If you are choosing to install a composite deck, make sure you get deck screws rated for composite decking.
Drywall Screws
When securing drywall to studs, it's essential that you get a specific type of screw. Drywall screws are self-tapping and boast a countersink design that result in a smooth finish when the drywall installation is completed. Make sure to use a drywall dimple bit when installing drywall screws to ensure a professional result. There are two different types of drywall screws available, those intended for wood studs and those intended for metal studs. Make sure to get the right type.
Masonry & Concrete Screws
When drilling into brick or concrete, you'll need durable screws designed to hold up to this tough material. Look for masonry and concrete screws. Typically, they feature a flat head with a hexagon indentation, although Philips head options are also available. Pre-drilling holes is required for installation. For the best results, pre-drill holed with a hammer drill and masonry bit. Once the pilot hole is drilled, the screw can be installed with a standard drill and a strong bit.
Additional Types of Screws
In addition to your most common varieties, you'll discover that there is a wide array of specialty screws available for completing specific projects.
- SPAX Self-Drilling Screws
- TORX Screws
- Binding Screws
- Machine Screws
- Sheet Metal Screws
- Tamper-Resistant Screws
- Lag Screws
Common Screw Features
As you start narrowing down your search for the ideal screw, you may start seeing special features listed. Understanding different screw features will help you home in on the best screw.
Self-tapping or Self-drilling: This term is used for screws specifically designed to drive in without a previously drilled pilot hole. This can reduce the time it takes to complete a project by eliminating the need to switch from a drill bit to a driver bit.
Countersink: Some screws are designed to have the head go slightly into the surface of the material. This is called countersink and it helps provide a smooth result when the project is completed.
Drilling Pilot Holes
If you aren't using a self-tapping screw, it's important to drill a pilot hole before driving in the screw. This will help prevent the wood or material you're using from splitting. Look at packaging for the screws you're using and use the drill bit size recommended on the packaging. The drill bit should be the diameter of the screw shaft, not including the added thread.
When you understand the different screw heads and the different types of screws, it's easy to stock up on the ones that will help you get professional grade results out of your project. If you are using a specific product, always check the manufacturer instructions for any recommendations on screws and fastening bits. The Home Depot Canada offers all the screws you need to install a simple wall shelf or build a complete deck. While you're there, stock up on the necessary drivers and tools needed to complete your project. Our professionals can help answer any questions you may have to ensure you get your project started off right.