For the few seconds they take to drive in, nails do a remarkable holding job. Yet for the little extra time it takes to drive in a screw, you get a tighter-holding fastener, a neater appearance, and another plus -- ease of disassembly. In fact, drywall screws teamed with cordless electric drills have created a mini-revolution in fasteners, including everything from deck screws to general-purpose wood screws.

screws

The most common slot configurations for screws are the slotted head and the Phillips head, which has an X-shaped slot. Square-drive screws are more rare, but are growing in popularity.

There are three head shapes from which to choose. A flathead screw can be driven flush with or slightly below the surface of the wood. Use ovalhead screws with trim washers for a finished appearance. Install roundhead screws when you want the screw head to show.

General-purpose or drywall screws offer an inexpensive and easy way to fasten items together. You can buy them by the pound, and they drive easily using a drill with a screwdriver bit. Trim head screws use a smaller Phillips or square-drive bit. They hold better than finish nails, but the countersink hole will be larger.

Use masonry screws (often referred to by the brand name Tap-Con) to fasten material to masonry or concrete surfaces. Simply drill the correct-size hole in the masonry surface and drive in the screw. Drive a hanger screw into a ceiling joist and fasten the object to be hung using the nut and thread on its lower half.

Use lag screws for heavy-duty fastening. Drill a pilot hole and drive in the screw with a wrench.

As with nails, screws should be three times as long as the thickness of the board being fastened. When buying screws, specify the gauge (diameter) you want. The thicker the gauge, the greater its holding power. Make sure you have the correct-size drill bit if drilling pilot holes (see the box at right). For more, see Fastening With Screws, Related Projects.

Machine bolts have a head that can be turned with a wrench. Carriage bolts have round heads for a finished appearance. When buying bolts, be sure to get the correct gauge and length; it must be longer than the materials you are fastening, so you can add the nut and washers. (For more, see Fastening With Bolts, Related Projects.) Thin metal can be joined with self-tapping sheet-metal screws.

Many carpentry jobs call for adhesives, either as the primary or secondary fastener. Purchase a supply of wood glue for general-purpose work, construction adhesive in tubes, two-part epoxy glue for extra-strong holding, panel adhesive for installing drywall or paneling, and perhaps a hot-glue gun with glue sticks.