Different Types of Screws And Their Uses

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 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.

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 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 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, 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.

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.