A bolt is a type of fastener that attaches two objects together. They are usually hex shaped to allow them to be turned more easily and they can come in different sizes.
Bolts are mainly made from steel and are coated in zinc to make them resistant to corrosion. They are used in a variety of applications, from cars to building constructions.
Grade 5
The hex head of these bolts provides a larger bearing and wrenching surface than socket products or machine screws. As a result, they are commonly used to fasten items together in a way that allows for future repair or maintenance disassembly. Typically, these fasteners are available in several grades. These grades indicate the tensile strength that the bolt can endure. Marsh Fasteners explains the differences between these grades, including what the head markings mean.
Grade 5 bolts are made of medium-strength carbon steel that has been hardened to increase their strength. They’re similar to the metric class 8.8 bolts, which can be identified by three evenly spaced lines on their heads.
These bolts are the strongest of all SAE American bolts, and they’re often used in heavy industrial applications. They’re also a great choice for critical mechanical applications that require high durability. They have a higher tensile strength than grade 8 bolts—120,000 psi for diameters up to 1 in.
Grade 8
As the most durable SAE American grade bolt, grade 8 hex cap screws are often found in manufacturing, repair and construction applications. Their six-sided hex head provides more substantial bearing and wrenching surfaces than socket products or machine screws, making them a clear choice for heavier duty applications.
They are made from medium carbon alloy steel that has been heat-treated, quenched and tempered to ensure maximum strength. Bolts of this grade are easily identified by their flat, hexagonal heads marked with six radial lines.
They are also available with a traceability stamp on the head that provides information such as the lot code, date of manufacture, heat treat batch, raw material batch and lab testing data for each individual fastener. This gives you complete assurance that the grade 8 bolts you have purchased are high-quality, and meet your specific application requirements. The Marsh Fasteners team has a large selection of grade 8 bolts available in different sizes and finishes.
Grade 10
Grade 10 bolts are made from low-carbon steel that’s been through case hardening, which increases their strength and durability. They’re often used in heavy industrial applications to join large structural parts and components together.
Whether you’re shopping for standard or metric hardware, it’s important to understand how each type of fastener is rated. The grades that are used on each type of bolt tell you how much stress they can withstand and which tools are suitable for tightening them.
The best place to start is by looking at the bolt head for markings that indicate its grade. These markings are typically in the form of letters, numbers, dashes, slashes, or dots. They can also include information such as the bolt’s diameter, thread pitch, and length. Once you’ve identified the grade, it’s time to select the right one for your project. The chart below shows how to read the various bolt grades so you can get the right fit for your needs.
Grade 12
Grade 12.9 bolts are known for their strength and durability. They are often used in manufacturing and construction industries to join large structural elements together. These bolts are quenched and tempered to achieve their high maximum tensile strength. They are also more expensive than other grades of bolts because they require a higher quality of steel.
The tensile strength of a fastener determines how much stress it can withstand before it breaks or stretches. Understanding this value is crucial when choosing hardware for your application. Marsh Fasteners explains the tensile strength, proof load and yield strength of different bolts so you can choose the right one for your job.
Bolts are typically made from a variety of materials and have varying grades. To identify the grade of a bolt, look for markings on its head. For example, bolts with a grade of 2 have three radial lines on its head, while those with a grade of 8 have six.US bolts
