Hods Screw Types Guide: The Right Screw for Every Job
Screws are the most common fastener in home improvement and woodworking, and using the wrong type causes split wood, failed joints, corroded connections, and stripped heads. The screw aisle at the hardware store has hundreds of options — different heads, threads, materials, and coatings — and most people grab whatever looks close enough. Here is how to pick the right screw for the specific job.
Screw Types Guide
Wood Screws
Traditional wood screws have a tapered shank with coarse threads that grip wood fiber, an unthreaded section under the head, and a flat or oval countersink head. The unthreaded shank section allows the top piece to pull tight against the bottom piece as the screw is driven.
Common sizes for woodworking:
- #6 x 1-1/4”: Light-duty — attaching hinges, hardware, thin stock
- #8 x 1-1/2”: General purpose — face frames, joinery reinforcement, medium stock
- #8 x 2”: Medium duty — thicker assemblies, shelf brackets
- #10 x 2-1/2”: Heavy duty — structural connections, thick stock
- #10 x 3”: Heavy structural — workbench assembly, framing connections
Head types:
- Flat head (countersink): Sits flush with or below the surface. The standard for woodworking. Requires a countersink bit or a combination drill-countersink bit for a clean installation.
- Pan head: Rounded head that sits above the surface. Used for hardware and applications where the head should be visible.
- Washer head: Built-in washer for increased bearing surface. Used in sheet materials and where the screw might pull through.
Construction Screws
Modern construction screws (GRK RSS, SPAX, Simpson Strong-Drive) have replaced traditional lag bolts for many structural applications. They are self-drilling, self-countersinking, and rated for structural loads.
GRK RSS (Rugged Structural Screw): Available in lengths from 2-1/2” to 10”. Star drive (T25 or T30). Self-drilling tip. Load-rated for structural connections — replacing lag bolts in many applications. $0.50 to $1.50 per screw depending on size. Excellent for deck framing, pergola construction, and structural workbench joints.
SPAX PowerLags: Similar to GRK. Self-drilling, structural rated, star drive. Slightly less expensive.
Simpson Strong-Drive SD screws: Designed specifically for Simpson connector hardware (joist hangers, post bases, hurricane ties). Do not substitute standard screws in Simpson hardware — the connectors are rated for specific fasteners.
Deck Screws
Deck screws are designed for treated lumber and outdoor exposure. They have aggressive threads, self-drilling tips, and corrosion-resistant coatings.
Coating types:
- Polymer/ceramic coated: Bronze, tan, or green colored. Adequate corrosion resistance for ACQ-treated lumber. Examples: GRK R4, Deckmate.
- Stainless steel (305 or 316): Maximum corrosion resistance. Required for coastal and high-salt environments. 3 to 5 times the cost of coated screws but outlasts the wood.
Standard deck screw size: #8 or #9 x 2-1/2” for 5/4 decking. #10 x 3” for 2x decking. Star drive (T25) is the standard — Phillips screwdrivers cam out constantly in the hard driving conditions of deck installation.
Pre-drill near board ends to prevent splitting. Treated lumber is more prone to end-splitting than untreated.
Drywall Screws
Coarse-thread screws with a bugle head designed for fastening drywall to wood or steel studs. Fine-thread versions are for steel studs; coarse-thread for wood studs.
Standard sizes: #6 x 1-1/4” for 1/2-inch drywall on wood studs. #6 x 1-5/8” for 5/8-inch drywall. Phillips head is standard (the only drive type that makes sense for drywall since torque is low).
Important: Drywall screws are not structural screws. They are hardened and brittle — they snap under lateral load instead of bending. Never use drywall screws for structural applications, furniture joints, decks, or anything that bears weight. They are designed for one job: holding drywall to framing.
Pocket Hole Screws
Specifically designed for pocket hole joinery. The Kreg system uses screws with a washer head, self-drilling tip, and fine or coarse threads depending on the material.
Coarse thread: For softwoods (pine, cedar, plywood). Fine thread: For hardwoods (oak, maple, walnut).
Use the Kreg-branded screws or equivalents with the correct thread type for your material. Standard wood screws in pocket holes do not seat properly — the head profile is wrong and the threads may not engage correctly.
Sheet Metal Screws
Self-tapping screws with sharp threads designed for metal-to-metal connections. Used in HVAC ductwork, metal roofing, electrical boxes, and attaching hardware to steel studs.
Hex-head self-drilling screws (TEK screws) drill their own pilot hole through sheet metal. Available in various lengths and head styles.
Drive Types
| Drive | Advantages | Disadvantages |
|---|---|---|
| Phillips (#2) | Universal, cheap drivers | Cams out under high torque |
| Robertson (Square, #2) | Zero cam-out, excellent grip | Less common in US |
| Torx/Star (T25) | Zero cam-out, high torque | Requires specific bit |
| Combination (square/Phillips) | Works with either driver | Jack of all trades |
| Hex head | Maximum torque, socket or wrench | Exposed head, no countersinking |
Star drive and Robertson are objectively superior to Phillips for every application except drywall. The extra cost of a T25 or #2 square bit ($2) eliminates the frustration of stripped heads, cam-out, and slipped drivers.
Material and Coating Selection
| Application | Screw Material |
|---|---|
| Indoor furniture | Zinc-plated or uncoated steel |
| Kitchen/bathroom | Stainless steel or polymer-coated |
| Treated lumber deck | Hot-dip galvanized, polymer-coated, or stainless |
| Exterior (non-treated) | Hot-dip galvanized or stainless |
| Cedar/redwood | Stainless steel (standard steel stains these woods black) |
| Aluminum connections | Stainless steel (avoids galvanic corrosion) |
Pre-Drilling and Countersinking
Pre-drilling prevents splitting, especially near board ends and in hardwoods. Drill a pilot hole sized to the screw’s root diameter (the shank minus the threads). A countersink bit adds a conical recess for the screw head to sit flush.
Combination drill-countersink bits ($3 to $8 each, sold in sets) drill the pilot hole and countersink in one operation. Essential for furniture building and trim work where flush heads matter.
In softwood thicker than 2 inches with the screw centered in the board’s width, pre-drilling is optional for modern self-drilling screws. Near edges and ends, always pre-drill.
Bottom Line
Use construction screws (GRK, SPAX) with star drive for structural work. Use coated deck screws for treated lumber projects. Use standard wood screws for indoor furniture and fine woodworking. Never use drywall screws for structural applications. Pre-drill near ends and in hardwood. Keep a supply of #8 x 1-1/2”, #8 x 2”, and #10 x 2-1/2” screws in both indoor and outdoor versions, and you cover 80 percent of workshop and home improvement fastening needs.