Fastener Types Guide
Choosing the right fastener is just as important as choosing the right tool. Each type of screw, bolt, and nail is engineered for specific materials and load requirements. Using the wrong fastener can lead to weak joints, material damage, or even structural failure. This guide covers the most common fastener types and when to use each one.
Wood Screws
Tapered shank with coarse threads designed to cut into wood fibers. Available with flat, round, or oval heads. The tapered design pulls the screw into the wood as it is driven.
Joining wood to wood, mounting hardware to wood, general woodworking projects
Flat (countersink), Round, Oval, Pan
Machine Screws
Straight shank with uniform threads designed to mate with tapped holes or nuts. Threads are finer and more precise than wood screws. Available in a wide range of head styles.
Metal-to-metal connections, electronics, appliances, machinery
Pan, Flat, Round, Hex, Socket cap
Sheet Metal Screws
Self-tapping screws with sharp threads that cut into thin sheet metal. Available with pointed or blunt tips. The threads extend the full length of the shank.
Joining sheet metal, HVAC ductwork, metal roofing, gutters
Pan, Flat, Hex washer, Truss
Lag Bolts (Lag Screws)
Heavy-duty fasteners with a hex head and coarse wood-screw threads. Much larger and stronger than standard wood screws. Require a pre-drilled pilot hole and are driven with a wrench.
Structural wood connections, deck framing, ledger boards, heavy timber work
Hex
Carriage Bolts
Round-headed bolts with a square shoulder beneath the head that prevents the bolt from spinning in wood. Tightened from the nut end with a wrench.
Wood-to-wood and wood-to-metal joints, playground equipment, fencing, furniture
Round (with square shoulder)
Hex Bolts
Six-sided head bolts that are tightened with a wrench or socket. Available in a wide range of sizes, materials, and grades. The most common bolt type for structural and mechanical applications.
General construction, automotive, machinery, structural steel connections
Hex
Drywall Screws
Bugle-headed screws with a Phillips drive designed specifically for attaching drywall to wood or metal studs. The bugle head sits flush without tearing the paper surface.
Hanging drywall, attaching gypsum board to studs
Bugle (Phillips)
Deck Screws
Corrosion-resistant screws designed for outdoor use. Typically coated or made from stainless steel with a star (Torx) or square drive to prevent cam-out during high-torque driving.
Decking, outdoor construction, fencing, pressure-treated lumber
Flat (star drive), Trim head
Concrete Screws (Tapcons)
Hardened steel screws that thread directly into concrete, brick, or block after a properly sized hole is drilled. No anchor required. Blue-coated for corrosion resistance.
Mounting brackets, ledger boards, electrical boxes, and fixtures to concrete or masonry
Hex washer, Flat Phillips
Self-Drilling Screws (Tek Screws)
Screws with a drill-point tip that can drill their own hole and tap threads in one step, eliminating the need for a pilot hole. Used extensively in steel framing.
Metal stud framing, attaching metal panels, HVAC work
Pan, Hex washer, Flat
Nails vs Screws: When to Use Each
Use Nails When...
Nails excel at resisting shear forces (side-to-side loading). Use them for framing, sheathing, and structural connections where building codes specify them. Nails are faster to drive, especially with a pneumatic nailer, and are generally less expensive than screws.
Use Screws When...
Screws provide superior withdrawal resistance (pull-out force) and allow for disassembly. Use them for decking, cabinetry, furniture, trim, and any application where you might need to remove the fastener later. Screws also clamp joints more tightly together than nails.
Use Bolts When...
Bolts with nuts and washers provide the strongest connections and are fully removable. Use them for structural steel, heavy timber connections, machinery mounting, and any joint that needs to be inspected, maintained, or disassembled periodically. Bolts distribute load over a larger area with washers.