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Complete Nut and Bolt Guide

Nuts and bolts are the most commonly used fasteners in manufacturing applications. They hold things together and ensure that they remain stable, sturdy, and secure.

Bolts are threaded fasteners used to securely join two or more components. They consist of a threaded rod, a head, and a shank. The bolt head can be hexagonal, square, or domed and may feature a washer component to provide a more even load distribution. Bolt is classified by their shape, length, and threading variety. Meanwhile, nuts are small, typically hexagonal-shaped metal objects with internal threads that match the threads on a bolt.

Chicago Nut & Bolt provides custom and standard fasteners for all types of applications, serving clients across various industries. We offer single quantities or bulk orders of hundreds of thousands of pieces. In addition, we can warehouse your order until you need it on the job site. Our commitment is to deliver fast and quality-tested services that align with your production policies.

Types of Nuts

Here are some of the most common types of nuts:

Coupling Nuts

Coupling nuts are cylindrical nuts that join two male threads. They are useful for extending the length of an installation.

Flange Nuts

Flange nuts have a round flange that acts as an external washer, providing even load distribution. They are similar to flange bolts and are commonly used in construction and automotive applications.

Hex Nuts

Hex nuts are hexagonally shaped and highly versatile. They require a wrench for installation and come in various types, including finished hex, semi-finished hex, hex flange, hex jam, heavy hex, and slotted hex.

Lock Nuts

Lock nuts secure other nuts and prevent them from loosening due to vibration or external forces. They come in different shapes, such as all-metal lock nuts with top or side locking features, serrated hex flange nuts, and nylon inserts.

Slotted Nuts

Slotted nuts are designed to form a locking mechanism with a cotter pin or safety wire. This makes them suitable for applications where high vibration or movement is expected.

Square Nuts

Square nuts are square-shaped and provide increased surface area and friction, reducing the risk of loosening. As a result, they are commonly used in industrial and construction settings.

Wheel Nuts

Wheel nuts are used to secure automotive wheels and come in various sizes and shapes, depending on the wheel type and vehicle.

Additional Nut Types

There are also custom-manufactured nut types, such as cap nuts, castle nuts, conical nuts, Keps nuts, thumb nuts, and wing nuts.

Types of Bolts

Here are some common types of bolts:

Carriage Bolts

These bolts have a domed or countersunk head with a square underside that prevents turning post-installation. Carriage bolts are commonly used with wood and masonry.

Flange Bolts

Flange bolts are a specialized type of hex head bolt with an integrated flange. This flange serves as a washer component to distribute the load.

Plow Bolts

Plow bolts are similar to carriage bolts, but some have a square-shaped countersunk top, while others have a domed design. These bolts are ideal for heavy-duty applications like industrial machinery.

Hex Head Bolts/Hex Head Cap Screws

These bolts are characterized by their hexagonal head shape and require installation with a wrench. They are available in many lengths and threading varieties. Hex head cap screws are the most common hex bolt category with tighter tolerances.

Square Head Bolts

Square head bolts have a square-shaped head that facilitates tooling gripping, allowing for easier installation.

Socket Head Cap Screws/Allen Bolts

Socket head cap screws have a flat chamfered top surface with smooth or knurled cylindrical sides. Forged heat-treated alloy examples are high-strength fasteners with special alloy formulations for the most demanding mechanical applications.

Additional Bolt Types

The other bolt types we can custom manufacture include anchor, belt (e.g., eye, hook, J, and U), countersunk, lag, and T-handle bolts.

Key Considerations in Selecting the Right Nut and Bolt Fasteners

Selecting the right nuts and bolts ensures optimal performance and safety. Here are some factors to consider when choosing:

Thread Type

There are two main types of threads: coarse and fine. Coarse threads are used for larger-diameter bolts and screws and are typically used in applications where strength is a priority. Meanwhile, fine threads are best suited for smaller diameters focusing on precision.


The most popular nut and bolt materials include steel, stainless steel, and brass. Steel is the most common and is suitable for most applications. On the other hand, stainless steel is corrosion-resistant and often used in applications where exposure to moisture is unavoidable. Lastly, brass is a soft metal widely used for decorative applications.


The size is determined by the diameter of the bolt or screw and the thread pitch. Choosing the wrong size can result in a weak or unstable structure.


The bolt’s grade and the nut’s material dictate strength. Higher-grade bolts are stronger and are typically used in applications where durability and longevity are a priority.


Different applications have different requirements, such as strength, corrosion resistance, and temperature resistance. Therefore, it’s important to choose a nut and bolt that best meet the needs of your project.

Applications of Nut and Bolt Fasteners

Here are the applications of nuts and bolts and their importance in different industries:


Custom bolts and nuts are widely used in steel structures, bridges, and buildings, where the ability to withstand high loads and stresses is critical. In construction, nuts and bolts connect structural members — such as beams and columns — to form a stable framework. They also join components in different building parts, such as roofing, cladding, and plumbing.


Engines, transmissions, wheels, and suspension systems utilize nuts and bolts to keep their components in place. Nuts and bolts in the automobile industry are engineered to endure high vibration, temperature, and pressure levels. They also help construct various sections, such as body panels, doors, and windows.


In the manufacturing industry, various types of machinery use nuts and bolts to hold different parts together. These custom fasteners used in machinery are designed to withstand high-stress levels and wear and tear. For example, they are utilized in assembly lines, conveyor belts, and production equipment.

Household Appliances

Nuts and bolts are also employed in household appliances, such as washing machines, dryers, and refrigerators. They hold different components, such as the motor, pump, and drum, in a washing machine.

Partner With Chicago Nut & Bolt for Reliable Custom Fasteners!

Chicago Nut & Bolt is your one-stop shop for high-quality bolts and nuts! We take pride in our extensive selection of standard and custom fasteners suitable for all applications, from mining and agriculture to military and construction. Whether you require small-scale orders or hundreds of thousands of pieces, we can fulfill your order precisely and efficiently!

We set ourselves apart with our ability to cater to one-off, low-volume, high-volume, and long-term production needs. Furthermore, our facility is ASME, ISO 9001:2000, ASTM, and SAE compliant, and we can accommodate many inventory strategies, including JIT and blanket orders. Our one-week delivery and emergency response can provide peace of mind knowing that we have your back when you need it most!

Contact us today to learn more about how we can help you in your next project!