Wood Screws

Wood screws join wood to wood and fasten hinges, brackets and other hardware to wood. Their threads draw the pieces together and grip without a nut. Get the diameter, length and head right, and you get a tight joint with the screw seated where it belongs instead of a split edge or a point sticking through the finished face.

Flat-head wood screws for a flush finish

Buy flat-head wood screws when you need the head flush with the surface. The flat top and cone-shaped underside let the head countersink into wood. That makes this head style right for cabinet work and hardware with matching countersunk holes.

A wood screw has a head, a shank and a tip, with large threads that bite into wood. Some have threads all the way to the head; others have a smooth section of shank. Flat head describes the head shape, while Phillips describes the recess your bit engages. Those are separate choices.

During Montana’s winter cabinet-renovation season, that distinction matters on every hinge and finished panel. Fit the head to the hardware hole first. A pan head has a flat underside and rounded top; a round head also remains above the surface. Buy the head that seats properly against what you are attaching.

Phillips flathead wood screws: choose diameter, then length

Phillips flathead wood screws give you a flush head and an X-shaped drive recess. Match the Phillips bit to the recess and keep steady pressure on it. A properly fitted bit is the first defense against a chewed-up screw head.

Start around #8 for general woodworking. Move down for fine pieces and small hardware, or up for thicker, heavier attachments. The number is the gauge, which identifies the diameter across the outside of the threads. It does not tell you the screw’s length.

These Phillips flathead sizes put the choice in concrete terms:

Screw gauge	Outside thread diameter	Length choices	Where to start
#4	0.112 inch	1 inch	Fine pieces and small hardware with matching holes
#6	0.138 inch	1/2 inch, 1 inch, 2 inches	Small hinges and drawer hardware
#8	0.164 inch	1/2 inch, 5/8 inch, 3/4 inch, 7/8 inch	Standard cabinet door hinges and general woodworking

The short #8 Phillips flatheads are useful when you need that diameter without a long point behind it. Choose among the 1/2-, 5/8-, 3/4- and 7/8-inch lengths by the thickness of the hardware or top piece and the wood beneath it. For small hardware that takes a #6, the 1/2-inch, 1-inch and 2-inch screws give you distinctly different reaches. Diameter and length have to be chosen separately.

For heavier door hinges and table aprons, #10 is a useful starting gauge. Its outside thread diameter is 0.190 inch. Match the hardware hole as well as the load; forcing a larger screw into the wrong hole does not improve the connection.

How long should a wood screw be?

Choose length by adding the thickness you pass through to the depth you need in the receiving wood, while leaving clearance at the back of a closed surface. For flat-head screws, length includes the head. Pan-head and round-head lengths run from beneath the head to the tip.

For 1 1/2-inch wood screws, remember this exact example: a screw through two 3/4-inch layers reaches the back face with no margin. That is too close for a finished cabinet face. Choose a shorter screw for that joint.

For 2 1/2-inch wood screws, 4-inch wood screws or 5-inch wood screws, use the same method. More length belongs in a joint with enough material to receive it. Length alone does not make a screw suitable for a structural connection.

If you ask for 1/4-inch wood screws, distinguish length from diameter. A #14 screw measures 0.242 inch across the threads, approximately 1/4 inch. A screw that is 1/4 inch long is an entirely different request.

For visible brass hardware, buy brass wood screws to carry the brass appearance through the screw heads: choose a #4 by 3/4-inch Phillips flathead for smaller matching holes, or a #8 by 3/4-inch or 1-inch Phillips flathead where the hardware takes a #8.

Stainless steel screws for pressure-treated wood decks

Buy greater corrosion protection for exterior work. Carbon steel is vulnerable to rust, and stainless steel is more corrosion resistant. Montana snowmelt and repeated wetting make that a working requirement on a deck or fence, not a cosmetic upgrade.

For pressure-treated wood deck screws, start with #10 by 2 1/2-inch stainless steel screws for 5/4 decking and #10 by 3-inch stainless steel screws for 2x decking. Match the length to the board thickness. When freeze-thaw damage sends you out to replace deck boards in spring, choose for the replacement boards you are fastening.

Stainless grades matter. Choose 305 stainless steel for ordinary non-coastal decks, fences and pergolas. Choose 316 stainless steel for heavy salt exposure or pool-deck conditions involving salt or chlorine. An indoor screw’s finish is the wrong starting point for these jobs, and thin zinc plating is not the deck choice.

If your search is for wood to steel screws, separate that job from stainless steel screws for wood. Stainless describes the screw material. Fastening wood to steel requires a fastener selected for the steel connection; a wood screw’s threads are designed to grip wood.

Structural wood screws for ledgers and timber connections

Buy the 3 5/8-inch FastenMaster LedgerLOK ledger screw for a deck ledger. That is a specific connection and a specific screw choice, separate from the Phillips flatheads used for cabinet hardware.

For structural work, use the specified, code-listed fastener for each connection. A ledger, joist hanger and post-to-beam joint place different demands on their fasteners. Connector-rated screws belong in the hanger connection; an ordinary wood screw does not become a connector screw because it fits the hole.

That distinction matters in the Flathead’s log homes and timber-frame work. A screw can be loaded sideways, pulled along its length or twisted during driving. Those are different strength demands. Choose by the connection, not simply by how substantial the screw looks.

Construction screws are part of the broader wood-fastener conversation, but the word construction is not a structural rating. Traditional lag screws are larger fasteners for high-load work and require predrilled holes. Treat the fastening design as the starting point for that work.

Drive wood screws without splitting the work

Match the threads to the wood they grip. Coarser threads suit softwoods such as pine; relatively finer threads suit hardwoods such as oak. The receiving piece determines that choice, not just the piece the screw passes through.

Drill pilot holes in hardwood and near board edges to reduce splitting. For a #8 screw, starting pilot-hole sizes are 1/8 inch in hardwood and 3/32 inch in softwood. Drive at moderate speed with steady pressure, then stop when the head seats. Overtightening can strip the threads or damage the wood.

Can you use drywall screws in wood? You can drive them into wood, but buy wood screws for wood joints. Drywall screws are made for fastening gypsum board and can snap under heavy driving torque. Use drywall screws for drywall and wood screws for your cabinet, furniture and hardware work.

Some sheet-metal screws can also be used in wood. For a wood-to-wood project, choose the wood screw by its diameter, length, head and exposure. That gives you a purchase based on the joint you are building.

The Pick

Buy Phillips flathead wood screws for cabinet work and countersunk hardware: #6 for small hinges and drawer hardware, and #8 for standard cabinet hinges and general woodworking. Choose the length that grips the receiving wood while keeping the point inside it.

Buy the #4 or #8 brass Phillips flatheads for visible brass hardware. For pressure-treated decking, buy #10 stainless steel screws, 2 1/2 inches for 5/4 boards or 3 inches for 2x boards. Buy the 3 5/8-inch FastenMaster LedgerLOK for a deck ledger.

Frequently Asked Questions

How do I choose the right size wood screw?

For most indoor furniture and cabinet builds, #8 wood screws between 1½ and 2 inches are a starting point, provided the joint has enough depth. Gauge tells you the diameter across the threads; length tells you how far the screw reaches. Check both pieces before choosing: a 1½-inch screw through two ¾-inch layers reaches the back face with no margin.

What type of screws should you use for pressure-treated wood?

For pressure-treated decking, #10 stainless steel wood screws are a starting point: 2½ inches for 5/4 boards and 3 inches for 2x boards. Those are decking examples, not sizes for every treated-lumber connection. A joist hanger needs connector-rated screws sized for the hanger, even when the surrounding lumber is pressure-treated.

Can you use drywall screws in wood?

Drywall screws can penetrate wood, but they’re made for fastening gypsum board and can snap under heavy driving torque. Use wood screws for wood joints, with a pilot hole in hardwood or near an edge. If you’re hanging drywall on wood framing, drywall screws belong in that job because you’re fastening gypsum board.

How do you drill screws into wood without splitting it?

Drill a pilot hole before driving wood screws into hardwood or near a board edge. For a #8 screw, starting pilot-hole sizes are ⅛ inch in hardwood and 3/32 inch in softwood. Match the bit to the drive recess, use moderate speed and steady pressure, and stop when the head seats. Extra tightening can strip the wood instead of making the joint tighter.

What does a wood screw look like?

Wood screws have a head, a shank and a tip, with large threads that grip the wood; some have a smooth section below the head. A flat head has a cone-shaped underside and seats flush, while an oval head has a similar underside with a rounded top that remains visible. Match that head shape to the hardware hole or the finish you want.

Are construction screws the same as wood screws?

Wood screws are a broad category, and the word construction doesn’t establish a structural rating. Choose a structural fastener for the particular connection rather than judging it by length or appearance. For a joist hanger, that means connector-rated screws sized for the hanger.

What are wood screws used for?

Wood screws join wooden pieces and attach hardware to wood, including hinges and brackets. For small hinges and drawer hardware, #6 is a starting gauge; standard cabinet door hinges commonly take #8. Match the screw head to the hardware hole so it seats properly.

What are wood screws made of?

Wood screws can be made from stainless steel or carbon steel, and brass is another option. Carbon steel is vulnerable to rust, while stainless steel offers greater corrosion resistance. For visible brass hardware, a brass screw carries the appearance through the head; for exterior work, choose the material and corrosion protection for the exposure.