Screws, like nails, are a common kind of fastener used to adhere different materials together. Whether you’re one for working with your hands or not, most people will need to use a screw for something at one point or another. Especially if you’re a homeowner, knowing the basic types of screws and how to use them will certainly come in handy one day. While screws may all look similar, they are in fact designed specifically for a wide variety of functions and uses. Read on to explore our guide to different kinds of screws and which screw will be best for your needs or projects.
Screw Design
Screws look an awful lot like nails, but their key differentiating characteristic is their ridges, uniquely shaped heads, and the tools used to drive them. Screws are used either with a screwdriver or with a drill, depending on the project. Screwdrivers are typically used for screwing screws into pre-made holes, such as in assembling furniture, whereas drills are used to directly insert the screw through wood or other materials.
The ridges around the cylinder are called threads, and they help secure the screw. The head of the screw comes in different designs depending on its driving instrument to ensure it can distribute the force effectively. The smooth area right below the head on some screws is called the shank. Screws can be made of many different materials such as stainless steel and aluminum, and they can be coated to promote durability and longevity.
Screw Types
Wood Screws
Wood screws are used for basic wood construction and woodwork projects to attach wood to wood. The coarse threads, smooth shank, and tapered head make wood screws an ideal choice for woodwork. Unless the screw itself is self-tapping, meaning it can be driven into the wood directly, then the screw will require a pilot hole, or previously drilled hole, before you insert it into the wood. Wood screws have different types of thread depending on the kind of wood. Typically, wood screws that have fewer threads per inch are best for fastening soft woods such as pine, whereas fine thread screws are best used for connecting hardwoods such as oak.
Wood screws can have many different kinds of heads, but typically have either a round head or a flat head. A round head will sit slightly above the wood on the finished product whereas the flat head will be more flush with the finished piece. Wood screws are available in interior or exterior styles with the appropriate finishes.
Deck Screws
Deck screws are similar to wood screws with a few extra specificities. Designed for decking, these screws are used to attach decking to a deck frame or composite decking. This style of screw is typically self-tapping, meaning it can be directly drilled into the material. It is corrosion-resistant to be more durable, especially for exterior use. The heads of deck screws are also designed to countersink, meaning to either sink slightly into the wood or to sit flush with it.
Drywall Screws
Designed for its name, drywall screws are used to install drywall. With its self-tapping head, designed to countersink without damaging the drywall, this style of screw is the standard fastener for securing sheets of drywall to wall studs or ceiling joists. Be aware, however, that this screw has a unique dimple on the head that requires a specific drill bit that doesn’t come in most standard drill sets.
Masonry Screws
Masonry screws are heavy-duty fasteners used to work with masonry and concrete. These screws typically have flat tips and a rounded hex head. Usually, holes must be predrilled before screwing and hammering in masonry screws.
Sheet Metal Screws
Sheet metal screws are designed for attaching sheets of metal, as their name suggests. They can also be used for wood or to secure other materials together, but they are primarily used for sheet metal. This kind of screw does not have a smooth shaft and typically has threading all the way up to the head to ensure they can easily drive through the sheet metal. Usually made from steel, these screws are designed to self-tap through metal, making them sharp and durable. Available in a range of sizes with sharp points and flat or hex heads, these heavy-duty screws are versatile and reliable.
Lag Bolts
Lag bolts, or lag screws and carriage screws, are large in diameter and long to deeply penetrate wood or other materials. Lag bolts are super durable and are coated in a corrosion-resistant coating to ensure they don’t degrade from exposure to elements or other construction corrosives. They are used to create very firm connections and are commonly found in decks, walls, and other outdoor structures. Carriage bolts, a kind of lag bolt, are used to fasten thick pieces of wood together and are more secure. Their round head design also makes them tamper-proof, which is ideal for outdoor structures in public places. Lag bolts often require other tools to drive into materials and a predrilled pilot hole.
Hex Bolts
Often used to fasten wood to metal, such as in furniture, hex bolts have a hexagon-shaped head, small threads, and a smooth shank. This style of screw is great for interior projects, but can also be found made from steel or galvanized for exterior uses. Hex bolts may require both a drill and a wrench for proper fastening.
Screw Versatility
Screws come in all kinds of shapes, materials, sizes, and functions, making them versatile and reliable fasteners. Be sure to check what screws are the best for your project.
While do-it-yourself projects can be fun and fulfilling, there is always a potential for personal injury or property damage. We strongly suggest that any project beyond your abilities be left to licensed professionals such as electricians, plumbers, and carpenters. Any action you take upon the information on this website is strictly at your own risk, and we assume no responsibility or liability for the contents of this article.
