How to Determine Which Grade of Bolt Your Farming Equipment Needs

By in

When people are working with the farming equipment you manufacture, they’re putting it through some rough conditions and terrain. Naturally, this means your farming equipment has to be tough in order to effectively withstand the pressures and loads that are being placed on it. To create strong equipment, you need sturdy components within in. Specifically, the bolts need to be high quality and durable. If they’re not, they can be quickly damaged by rain, heat, stresses, leaks, and rust, rendering your equipment useless.

A bolt’s strength is expressed in terms of its grade. The grade of bolt chosen for your farming equipment needs to coincide with the job the bolt is meant to do. Choose the wrong grade of bolt and you’ll have useless machines that break down quickly. Choose the right grade and you’ll have equipment that your customers can depend on for the long haul.

General Differences of Grades

To determine which grade of bolt your farming equipment needs, you must first understand the different options you have to choose from. There are many different grades to pick from, which are differentiated by the markings on the bolt’s head. These markings provide proof that the bolt meets the strength standards of the Society of Automotive Engineers (SAE) for conventional sized fasteners and the European Community for metric fasteners. These markings are associated with specific tensile strengths, which is the maximum load in tension that a bolt can handle before breaking, and different materials.

Bolts used in most farming equipment should be manufactured with quenched and tempered carbon steel, though stainless steel bolts made from nickel and chromium are also sometimes used. Stainless steel bolts offer better corrosion resistance, but are generally a higher cost to purchase.

Different Options

Now, let’s look at the most common options of bolt grades that you have to choose from. First, you have Grade 2, which are used when there is no structural load required. This type of bolt has no head markings, is made from low or medium carbon steel, and has a proof load of 33,000 to 55,000 psi, minimum yield strength of 36,000 to 57,000 psi, and minimum tensile strength of 60,000 to 74,000 psi. 

Grade 5 bolts have three radial line markings on the head and are made from quenched and tempered medium carbon steel. These have a proof load of 74,000 to 85,000 psi, minimum yield strength of 81,000 to 92,000 psi and minimum tensile strength of 105,000 to 120,000 psi. Most plow bolts are grade 5, although in certain applications, grade 8 can be used.

Grade 8 bolts are significantly stronger, which is why almost all grain bin bolts are made of this grade. They have six radial lines on their heads. They’re made from quenched and tempered medium carbon alloy steel, have a proof load of 120,000 psi, minimum yield strength of 130,000 psi and minimum tensile strength of 150,000 psi.

The Right Grade for Quality

The durability and strength of the bolts you’re placing in your machines are important to the quality of the bolts and the overall usefulness of the farming equipment you manufacture. The bolt’s load resistance, tensile strength, and yield strength are affected by the grade of bolt you choose. Also, always use the proper grade of nut to match your fasteners grade to achieve the full strength of your fastener needs. If you’re unsure, contact the manufacturer of your equipment for the proper grade of fastener to be used. A reputable manufacturer with great customer service can walk you through the different options so you can ensure that you’re choosing the right grade of bolt for your farming products, which will lead to maximum performance.

White Paper: JS Plus™ Plating

Discover a New Superior Plating Option