Differences Between Bolts and Set Screws

Choosing the right industrial fastener is an essential part of every construction or manufacturing build. The generic name ‘bolt’ is typically used interchangeably to describe both bolts and setscrews. They may look similar; however, their application and usage are different depending on the material you're joining and the type of joint specified by the engineer.

If you're wondering what the difference is between bolts and set screws, you're not alone. Many people confuse the two!

Deciding which one to use can make a big difference to the overall strength of your project. It can also make it much easier - or more difficult - to connect your material.

Are you trying to decide whether a bolt or set screw is the best fastener for your project? In this article, we will explain the difference between the two and look at some common applications. 

 

Understanding the Difference between Bolts and Set Screws

The biggest difference between these two different types of fasteners is to do with the shank of the fastener. Bolts are only threaded along a section of their shank and have an unthreaded section close to the head. In contrast, setscrews are fully threaded.

Bolts are typically designed to connect with a hex nut and are normally tightened or released by turning the nut.  Additionally, bolts must protrude through the components that they are connecting to securely tighten the nut. In some cases, the head and the nut are recessed into the material, but the principle is still the same. You use bolts in unthreaded holes as the tightening force comes from the nut.

In contrast, setscrews are tightened and released by turning their hex head of the fastener.

Setscrews are inserted into holes with an internal thread such as the engine of your car. This means that set screws are not connected with a nut. Instead, they join two components together by tightening against the internal threading of a component.

Set screws typically do not protrude from the components they are joining. The entire shank of a set screw fits into the threaded hole. 

 

When to Use a Bolt

Bolts are used, along with nuts, in applications that require a high level of clamping force. High-grade bolts are extremely reliable and are used in the construction of critical load-bearing joints. Additionally bolts are used where there is potential for the two materials being clamper could move or where vibration could occur. This is because the unthreaded section of the bolt that goes through a whole can withstand greater shear forces. A setscrew on the other hand may fail or become damaged if the exposed threads in the hole are subjected to repetitive shear forces..

Bolts are often attached with a washer. This helps to spread the load on the bolt head over a larger area and stops it from sinking into a softer material, like wood. Additionally it protects the materials from being damaged by the bolt or nut during tightening.

 

Different Types of Bolts

There are many different types of bolts that are specifically designed for different applications. Bolts are generally larger in size compared to set screws, making them more suitable for high-strength applications.

Some examples of different types of bolts are:

  • Anchor Bolts - used to connect structural components to concrete
  • Blind Bolts - high strength bolts with a locking pin mechanism
  • Eye Bolt - have a ring instead of a head to connect cables or shackles
  • Hex Bolt - have a hexagonal head

 

Are You Looking for Industrial Fasteners?

If you're looking for bolts or set screws, Konnect Fastening Systems has a wide variety of options available. 

You can browse through our range of fasteners and shop online.

Alternatively, if you'd like to speak to one of our fastener experts about your specific application, call us on 1300 KONNECT (566 632).