Last time we looked at three of the more common screws you’re likely to use around the house. Here are a few more.
Machine screws or appliance screws are in a way more akin to bolts. Their threads — which are finer than wood screws — are designed to thread into a nut or tapped hole — usually in metal.
Self-tapping sheet metal screws hold two pieces of sheet metal together, such as the brackets that hold downspouts in place. They have sharp points which pierce thin sheet metal, and then their coarse threads cut and grab onto the edges of the hole. They’re usually short — just long enough to get through both pieces of metal.
Lag screws or lag bolts are heavy screws which are driven into wood with a hex wrench to carry large loads. Combined with an anchor, you can use them to fasten things to concrete and brick.
Roundhead screws. Unlike flathead wood screws, these screws are not designed to be countersunk. Use them when you want the screw exposed, for a more attractive look, or when attaching thin material to wood. They can also be easily removed without risking scratching the surface.
Stainless steel or aluminum screws stand up to moisture. Brass does, too, but the screws are softer, and more often used to match hardware. Coated deck screws are an economical way to use screws in outdoor areas.