5 Types Of Bolts And What They Are Best Used For

Bolts are essential tools to have in your home toolbox as you can never know when they might come in handy. These tools are a part of the threaded fasteners family and are often used with threaded nuts. Sometimes the two are paired with more components depending on the job that needs to get done.

There are multiple different types of bolts that are typically categorized according to their strengths, materials, head shapes, and finishes. They all are used differently and play a role in completing different tasks. Here are some of the most commonly used bolts and their uses, classified in different categories:

 

Classified In Head Shapes

Bolts come in different head shapes. These include square, slotted hex, socket cap, and hex. Some of these bolt types include:

• Anchor Bolts

These are bolts that have one threaded part on one end, while the other end is non-threaded and has an L shape. They are used in applications such as security light poles. 

• Carriage Bolts

These are threaded on both ends and have a smooth head and a ribbed undercut. These features ensure maximum performance and especially help the bolts stay intact when in use. They are mostly the kind you will see fastening metal to wood.

• Eye Bolts

Eyebolts have one loop end and one fully threaded end. They are mostly used to lift components such as a wire in light rigging.

• Hex Bolts

These have six-sided heads and could either be fully or partially threaded. They are used in multiple ways of applications including in the construction of highway elements and repair of docks, etc.

• Machine Bolts

These are fully threaded, have square heads, and paired with semi-cone points. Some of their applications include fastening wood to wood, wood to metal, metal to metal, and more.

 

Classified In Bolt Strength

Bolt’s strength is specified by markings on them. This is also usually determined by materials and the dimensions used. Here are some bolt types classified by their strength:

• Low/ medium carbon steel, which has grade 2 marking.
• Medium carbon alloy which is grade 8 and metric class 10.9
• Alloy steel at class 12.9
• Stainless steel at grade 18-8 and class A-2.

 

Bolt Classified By Finishes

This mostly refers to the coating of the bolt. The finishes could either be of high or low quality depending on the use and application. Some of them are as follows:

• Plain finish – These are bolts with no coating at all. They are also referred to as natural or self-color. 
• Zinc plated – These are bolts coated with zinc. They are thicker and provide great resistance to corrosion. They are also inexpensive as compared to other bolts, making them commonly used. They provide a good-looking smooth finish and paint surface if need be.
• Class 3 – These are bolts with zinc/ tin coats. They have a thicker coating compared to other bolts like zinc plated, highly resist corrosion, and give a better fit to sockets compared to others like HDG.

 

Classified With Bolt Material

Bolts are used for various applications; some for heavy duties others for lighter duties. Selection of material is therefore important, depending on use. Some of these materials include:

• Steel

These are some of the most commonly used bolt types. They are highly formable, have great strength, and are durable. They are also cheaper than most, widely available, and therefore the most used types. They also come in different alloys, with different strength degrees, to suit different uses.

• Stainless Steel

These are a combo of low carbon steel, chromium, and nickel. It is highly resistant to corrosion, hardly hardens, and can either be austenitic or martensitic.

• Bronze and Brass

Bronze is a mix of tin and copper while brass is copper and zinc. These provide high corrosion resistance, making them of great use in aquatic applications.