Part of doing any project means having a reliable fastener like a screw. But with so many different screw types to choose from, it can be difficult to know which one is which.

Self-tapping screws are extremely valuable for getting many home and professional projects done, making it one of the most versatile screw types you’re going to find. Let’s learn more about self-tapping screws, the different kinds, their use in projects and gadgets, and so much more.

What are self-tapping screws?

Depending on the material type you work with, there may or may not be a need for a pre-drilled hole. That pre-drilled hole called a pilot hole, is meant to reduce the torque and stress to that material’s surface. Doing so can prevent cracking, bending, warping, and any other damage that could happen to the surface of the material.

Self-tapping screws are meant to be used on certain materials to mitigate the need for a pilot hole. By simply driving the screw into the material, the cutting thread will work its way into the material, securing the two sides together. You generally want to use self-tapping screws for bringing plastic, metal, brick, and wood together securely.

What are the types of self-tapping screws?

There are two subsets of self-tapping screw types to be aware of. Depending on the application, one can be better to use than the other. Let’s look at thread-forming and thread-tapping screws and what they are used for.

Thread-tapping screws. Thread-tapping screws don’t require a pilot hole, but you can definitely do one to make the process a bit easier. Just make the pilot hole smaller than whatever your screw’s diameter is. Thread-tapping screws create a path for the screw by stripping away material. The only bad thing is that you can wind up stripping the threads on these screws, in which case you should go up the next size.

Thread-forming screws. Thread-forming screws will require a pilot hole. That’s because this type of self-tapping screw doesn’t have a pointed tip that can bore into the material. You typically want to use these to join plastics together since they can grip a bit more tightly without doing damage to the plastic (cracking, mostly). Just make sure that you don’t overtighten them because that is where you will run into major damage issues.

The most common types of self-tapping screws

The handier you get, the more projects that you will ultimately take on. This means that you are going to run into different kinds of self-tapping screws that work for specific purposes. Here are the most common self-tapping screws that you will run into at one point or another.

Allen/Socket head. This kind of self-tapping screw keeps the head of the screw from getting distorted through the driving process. Most of the time you can install these screws with a simple Allen wrench, though you might need an adaptive driver.

Countersunk/Flat head. For aesthetic reasons, having a countersunk head is the right option. You can get a smoother, flatter finish that just looks better than other screw types.

Flange head. If you are going to be joining plastic to plastic or metal to metal, the flange head screw is the best option. That’s because you get far more clamping torque than you would get with one of the other head types.

Bugle head. This is easily confused with the countersunk option. Bugle heads are great for attaching plasterboard to metal or wood studs thanks to the concave bearing face. It also distributes stress over a wider area than the countersunk version.