Screws
One of the most common fasteners available is the screw. It may resemble a nail but this fastener is far more versatile and can hold much greater of a load. We'll look at different types of screws and screw sizes.
Sheet Metal Screws, Wood Screws, Machine Screws and Drywall Screws are some of the more common screw fasteners you will use in your projects.
Wood Screw
Drywall Screw
The Drywall Screw has many useful applications beyond hanging drywall. A bucket of drywall screws of various sizes 1", 1 5/8", and 2" screws are some of the more useful although I have a box of 4" screws around as well. I always prefer the coarse thread screws as they are far more useful. The thin and sharp threads tend to do less damage to wood and more brittle materials like particle board, OSB and cork. A drywall screw is a self-tapping screw which means it cuts it's own threads in a material. The wide threads of the drywall screw also make it ideal for assembling and reassembling. For instance, I used drywall screws to hold together a shelving unit I built for college. Every year I took the shelf apart and reassembled it the following year. The drywall screws engaged the wood every time and the shelf held many heavy textbooks without fail.
Machine Screw
The machine screw is a bit different than the first two varieties. A machine screw is not tapered and does not have a point at the end of the shank. The thread and size of machine screws are very precise and designed to fit in a predrilled and tapped hole. Stainless steel screws, zinc plated steel and brass machine screws are some of the most common varieties. Some machine screws have square threads as opposed to the more typical triangle threaded screws. While more difficult to cut, it results in an extremely accurate thread and is often used when the depth of the screw is critical to the application.