Nuts are key components in many construction and DIY projects, acting as fasteners for bolts and screws. Here’s a list of some of the most prevalent types of nuts and their applications:
Acorn / Cap Nuts
Used for decorative and safety applications, these nuts have a domed top to cover exposed threads, protecting them and reducing the risk of injury.
Cage Nuts
These are square nuts enclosed in a spring steel cage, allowing for easy installation in square holes. They’re commonly used in rack mounting and electronics.
Castle Nuts
Characterized by their slotted, cylindrical top, castle nuts are used with a cotter pin to prevent loosening. They’re often used in automotive and machinery applications.
Clinch Nuts
Also known as press-in nuts, clinch nuts are used in thin sheet metal applications where they’re pressed into the material to provide a threaded insert.
Conduit Locknuts
Designed with minimal surface area and protruding lobes, these nuts allow for low-profile installations and can be hand-tightened.
Coupling Nuts
These nuts have internal threads at both ends, allowing for the joining of studs and bolts. They’re used in applications where lengthening a fastener is needed.
Finished Hex Nuts
The most common and versatile style of hex nut, used in a wide range of applications. They’re available in various materials, including steel and stainless steel.
Flex Locknuts
These nuts have a segmented collar that creates a prevailing torque locking action when tightened, preventing loosening under vibration.
Heavy Hex Nuts
Thicker and wider across the flats than standard hex nuts, heavy hex nuts are used in structural applications and are available in various grades and finishes.
Hex Flange Nuts
These nuts have an extended flange that acts as a built-in washer, providing a larger bearing surface. Some versions have serrations for additional locking strength.
Hex Jam Nuts
Two-thirds thinner than standard hex nuts, jam nuts are used as a locknut or when space is limited. They’re available in multiple materials, including stainless steel.
KEPS K-Lock Nuts
These nuts have an attached free-spinning washer, providing extra hold. Standard KEPS nuts have an external tooth lockwasher, while conical KEPS nuts have conical washers.
Left Hand Threaded Hex Nuts
These nuts tighten to the left side and are used in applications where reverse threading is required.
Machine Screw Nuts
Thinner than finished hex nuts, these are used with machine screws and are available in hex and square options in steel and stainless steel.
Metric Nuts
Available in various styles, including acorn, hex, flange, and wing nuts, metric nuts are used in applications requiring metric measurements.
Mil-Spec Military Grade Nuts
Hex nuts that meet military standards and come with a manufacturer’s certification. They’re used in applications where high reliability is required.
Nylon Hex Nuts
Standard-sized hex nuts manufactured in nylon, providing insulation and resistance to corrosion.
Nylon Insert Locknuts
These nuts have a nylon insert that restricts movement, providing a locking action. They’re available in light hex, heavy hex, and metric options.
Panel Nuts
Used in switch and electrical applications, panel nuts offer a smaller surface area than standard nuts.
Rack Mounting Cage & Clip Nuts
Used for rack mounting in sizes 10-32, 12-24, and M6, these nuts are made of steel with a zinc finish.
Rivet Nuts / Threaded Inserts
Available in large flange, small flange, and ribbed options, rivet nuts provide a threaded insert in materials where threading is not possible.
Slotted Hex Nuts
These nuts have slotted cuts in the top for the insertion of pins, providing a locking mechanism.
Square Nuts
Available in standard and heavy styles, square nuts offer a larger surface area for wrenching and are used in various applications.
Stover Locknuts
All-metal locknuts with a controlled distortion of the top threads for a locking action.
Structural Nuts
Used with structural bolts and washers in construction and infrastructure projects.
T / Tee Nuts
Available in 3, 4, and 6-prong styles, T-nuts are used in wood and furniture applications.
Tinnerman Style Nuts
Used in various applications, Tinnerman style nuts include cage, clip, J type, U type, flat type, and hat style nuts.
Two Way Reversible Locknuts
Prevailing torque type locknuts with indentations on the flats for a locking action.
Tab Weld Nuts
Used in welding applications, tab weld nuts come in multiple configurations, including hex projection, round base, and square weld nuts.
Wing Nuts
Available in stamped, cold-forged, and washer-based styles, wing nuts are hand-tightened and used in applications where frequent adjustments are needed.
Each type of nut has a distinct purpose and is intended to provide a secure and dependable fastening solution for a variety of applications. Understanding the many types of nuts and their applications can help you select the best one for your project.