Two screws that look alike
A box of drywall screws and a box of wood screws can look similar on a shelf, and both can be driven into a piece of lumber. That is why drywall screws are so often pressed into service for other jobs. They are inexpensive, widely available and quick to drive. But they are designed for a specific task, and the differences matter when a joint has to carry weight.
How drywall screws are made
Drywall screws are built to hold sheets of gypsum board against studs.
- Bugle head. The head curves outward like a trumpet. This shape lets the screw pull the paper-faced board tight and settle just below the surface without tearing the paper, ready to be covered with joint compound. It is also why a drywall screw is not a good fit for a flat countersunk hole in hardwood.
- Hardened, brittle steel. They are typically heat-treated to be hard so the points can penetrate and the heads resist stripping from a power driver. The trade-off is that they tend to snap under sideways loading instead of bending first.
- Thread. Coarse-thread versions are usually meant for wood studs, while fine-thread versions are intended for thin metal studs. The thread is cut along most of the length.
- Point and finish. A sharp point speeds starting. A dark phosphate coating is common, and some are plated. These coatings offer limited corrosion resistance, so they are intended for indoor use in dry conditions.
- Drive. Most use a Phillips-style recess, or a similar one made for drywall bits. The topic of recess shapes is covered in the article on screw drive types.
The drywall job itself is covered elsewhere, including hanging drywall and the later step of drywall mud.
How wood screws are made
A traditional wood screw is designed to join pieces of wood and to carry load.
- Shank and thread. Many have a smooth, unthreaded section just under the head, plus a threaded lower portion. When the top board is drilled with a clearance hole, the smooth shank slides through it freely and the threads grab only the bottom board, so tightening pulls the pieces together. The anatomy is covered in the article on pilot holes.
- Head styles. Flat heads are designed to sit flush in a countersunk hole. Round and pan heads sit on top of the surface.
- Softer, tougher metal. The steel is typically less brittle, so the screw is more likely to bend than snap, though quality varies considerably between products.
- Sizes. They come in a range of gauge sizes and lengths, with a wider selection of finishes such as zinc, brass, bronze and stainless steel.
Modern structural or construction screws take this further, with hardened but tough steel, special heads and thread forms, and published load ratings. Those are different products from either of the two covered here.
Where drywall screws belong
- Fastening drywall to wood or metal studs.
- Temporary jigs, shop fixtures and bracing where a failed screw would cause no harm.
- Light, interior work where the screw is mostly holding something in place rather than carrying a load.
- Pulling thin panels, such as underlayment or cabinet backs, tight to a frame, where the manufacturer allows it.
Their sharp coarse thread does hold well in softwood, which is a big part of why they are popular for casual use. Even so, drywall screws should not be used where strength matters, and they are often a poor choice for outdoor work because the coating is not intended to resist moisture.
Where wood screws belong
- Furniture, cabinets and other woodworking where the screw is part of the joint.
- Hinges, hardware and brackets, using the screw type that suits the hardware.
- Any joint where a snapped screw would be a safety problem, together with the correct type for the job. For decks, fences and other exterior work, use screws labeled for outdoor use and for the lumber involved; the corrosion article explains why treated wood needs compatible hardware.
Practical differences when driving
Drywall screws are often driven with no pilot hole because the thin, sharp shank displaces wood easily. In hardwood or near board edges, though, the same approach can split the board or snap the screw, particularly with a powerful impact driver. Wood screws in hardwood nearly always need a pilot hole. Whichever you use, set the drill clutch or ease off the trigger so the head does not strip or break.
The head recess on either kind can strip. If that happens, the article on removing stripped screws covers some ways out.
Quick comparison
| Feature | Drywall screw | Wood screw |
|---|---|---|
| Head | Bugle | Flat, round or pan |
| Steel | Hard, brittle | Usually tougher |
| Thread | Full length, fine or coarse | Often partial, with a smooth shank |
| Typical use | Drywall, light fastening | Joinery, furniture, hardware |
| Structural use | Not recommended | Depends on type and rating |
Safety
Wear eye protection when driving or cutting screws, because a brittle screw can break and fly. Wear a dust mask when working with drywall, since the dust is a nuisance to lungs. Where a fastener supports a person or heavy load, follow the plans, local codes and manufacturer’s ratings. This is general information, not professional trade advice.