Difference Between A Screw and A Bolt

The Difference Between Screws and Bolts

Even professionals are befuddled sometimes on which screw is the best screw for the job! I mean, when you are putting screws in to wood, then they must be wood screws right? Well, maybe…….but do all of you know that if a screw is fully threaded and does not have a significant shank underneath the head, then you are going to be looking under the wrong category for your screw. Here is just a little basic information to get you started.

What do you get and why? Screws can be divided into types and then descriptive features. Because the term, ‘screw’, is so general it can be very confusing when looking for what you need for any given project. Various types of screws have been designed for fastening different types of materials together. Some common names are wood screws, sheet metal screws, drywall screws, deck screws and masonry screws. Often, it is a specialized thread that makes the difference or it could be the color. There are confusing names like ‘machine screw’ which is really a bolt but, since it has screw threads on it, it can be called a screw. Then there are Lag bolts which are really very large wood screws but have a hex head for driving the screw in and so people have begun calling them bolts. Often, local names differ but if you ask for a fastener by name of material first, it’ll at least get you started. Screws generally refer to threaded cylinders with a point. Bolts are threaded cylinders with a blunt end and take a nut.