Ever wonder what the difference is between a bolt and a screw? Both are used to fasten things together, but they achieve that in different ways. Read on to learn about the different types of bolts, screws, and fasteners—and what they’re typically used for.

Bolts vs. Screws

The easiest way to explain the difference between a bolt (like a hex bolt), and a screw (like wood screws) is that bolts are meant to be used together with a nut, while screws are meant to be driven into wood or another type of material. Both types of fasteners are tightened by turning them in a clockwise direction.

Bolts are generally thicker and wider than screws, and they usually have a head that sticks out on one side. The head of a bolt is called the external hex, and it can be turned with a wrench. The other side of the bolt has threads that match up with the threads on a nut. When the bolt is inserted through a hole in two pieces of material and the nut is threaded onto the bolt, tightening the nut pulls the two pieces of material together.

Screws also have threads, but they’re tapered so that they can be driven into wood or another type of soft material. The head of a screw can come in many different shapes, but it’s usually designed so that it can be turned with a screwdriver. There are also specialized screws that can only be turned with specific types of tools.

Difference Between Wood and Machine Screws

There are all sorts of different types of bolts, screws, and fasteners—each designed for specific purposes. Here are some common types of fasteners and what they’re typically used for:

Wood Screws

These are usually made out of brass or steel. They have sharp points and threads that allow them to easily be driven into wood. Wood screws come in all sorts of fluted or unthreaded shank designs.

Machine Screws

These have machine threads rather than wood threads. They’re typically made out of steel or zinc-plated steel, and they come in Phillips or slotted heads. Machine screws are often used to fasten metal parts together.


As you can see, there’s a lot more to bolts, screws, and fasteners than meets the eye. Different types are designed for different purposes, so it’s important to choose the right type for your project.