What Grade Bolt is the Strongest and Why?

Learn how to choose the right mechanical fastener for the project that you’re doing.

Bolts are everywhere. They’re part of commercial and industrial products and make up complex machines and simple gardening tools. From a manufacturing standpoint, bolts are among the most produced mechanical fasteners available. They come in different grades to help people better understand their intended use.

Read below to learn how bolts receive a grading and why things such as proof load and tensile strength matter. When you’re ready to buy bolts for your machinery or tools, you’ll know precisely what to buy based on the knowledge shared here. You can shop our online catalog with the greatest of ease.

How are Bolts Graded?

Bolts have a grading in an attempt to thwart improper usage of them. When misused, they can become a liability. Matching the job with the bolt grade allows you to purchase the right type of bolt for your project every time that you buy the mechanical fastener.

The grading system for bolts is numbered based on the material used, diameter, proof load, and tensile strength. The material is typically low to medium carbon alloy steel. The tensile strength refers to how much pressure it can withstand with a Grade 2 bolt having a 74,000 psi and a Grade 5 bolt having a 120,000 psi.

Commercial-grade 8 bolts are the strongest option available. They’re made from medium carbon alloy steel and have markings that include six raised dashes. The psi of the bolt is 150,000, meaning that it can withstand great deals of pressure because of the way it was quenched and tempered.

Why Bolt Strength Matters

The mechanical fastener that you choose receives a grading, which indicates the way that you plan to use it. That’s why it’s important to select the strongest bolt available for durability purposes. You have less of a chance of the bolt slipping, falling out, or rusting based on the way the manufacturer grades it and the time you put into learning about its rating and suggested uses.

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