
Screws and bolts tend to spring to mind when fasteners are the topic of discussion. After all, in the world of fasteners, these are by far the most common. However, the world of fasteners is much bigger than just nuts, bolts, and screws. There is a wide range of other fastening options that offer unique advantages, depending on your application. For instance, the clevis fastener is frequently used to secure loads to machinery, trailers, pickup trucks, and more. Such versatility makes the clevis fastener a viable solution in an array of scenarios.
What Is A Clevis Fastener?
A clevis fastener is a U-shaped or hook-shaped fastening device with two holes that hold a pin in place. The clevis’s two holes exist in the open section, where each one is found on a respective prong, supporting the usage of a pin.
A pin gets inserted through the two holes when the clevis is positioned correctly. Furthermore, the clevis fastener includes the three following pieces:
- Clevis
- Clevis Pin
- Tang
There also might be a split pin that secures the pin. Resemblant of a bolt, the clevis pin differentiates itself because it’s either unthreaded or partially threaded with a cross-hole for the split pin mentioned above. The tang is a piece held in place by the clevis pin, fitting in the space within the clevis. When a simple clevis is fitted with a point, it’s usually referred to as a shackle. But it’s worth noting that this combination is only one example of a shackle.
Lastly, clevis fasteners are often used in the following machines:
- Automobiles
- Aircrafts
- Boats
- Construction equipment
The Parts of a Clevis Fastener
Let’s take a closer look into the various parts found in a clevis fastener:
-
Clevis Pin:
This part of the clevis fastener holds the tang firmly in place, keeping it attached securely to the clevis.
-
Clevis Hanger:
The hanger has both a U-shaped clevis and a V-shaped clevis. In the V-shaped clevis, there’s a hole in the flattened area at the base. The components are joined together with a pin or bolt. Clevis hangers offer vertical pipe adjustments, making them ideal for pipe attachments.
-
Clevis Hook:
This hook doesn’t have a snap lock, but it does have a clevis and pin (or bolt) at the base. The hook gets fastened to a bracket or chain by the clevis.
-
Clevis Hitch:
A clevis hitch is used for towing purposes (e.g., for a trailer). Typically, clevis hitches are combined with lunette rings. And some of the attachments might be compatible with tow balls.
-
Clevis Shackle:
A U-shaped piece of metal that’s fastened with a clevis pin/bold across the opening. It can also be secured with a hinged metal loop connected with a locking pin mechanism with quick-release capabilities.
-
Clevis Rod Ends:
Clevis rod ends are either machined or folded pieces molded into a clevis. At its base, the end is fitted with a hole. Here, a rod is attached. The hole is typically threaded in machined pieces.
-
Clevis Bolt:
Clevis bolts are best used when large shearing stress occurs but are never in tension. These special-use bolts have slotted brazier-type heads.
-
Clevis Bracket:
Usually, clevis brackets are solid metal pieces and have flat rectangular bases. They have holes fitted for bolts and machine screws. Clevis brackets also have two rounded wings parallel to one another. This forms a clevis. These brackets are used in automobiles and airplanes, mounting rods to flat surfaces.
Threaded vs. Unthreaded Clevis Pins
A clevis can be secured by either a threaded or unthreaded clevis pin. While they look very similar, there are some key differences between the two. Unthreaded pins are easily identified by their rounded head on end and a cross-hole at the other end. These pins do not screw into the clevis but instead slide into place.
Threaded pins have threading or partial threading on one end of the pin with a formed head on the other end. Since they can be either fully or partially screwed into the clevis, threaded pins provide better stability and security compared to their unthreaded counterparts.
The Different Types of Clevis Fasteners
The shackle is the most regularly used type of clevis fastener. It consists of a clevis, a tang, and a clevis pin. This is what one would be referring to if they were discussing a “standard clevis.” Another popular type of clevis is the bracket. This fastener has a rectangular-shaped hook that has holes for screws, bolts, and other fasteners.
There are also a number of specialty clevis fastener options available such as the clevis hanger. These consist of two clevises, offering both a V-shaped clevis and a U-shaped shackle clevis. Together, these components connect and use a fastener, such as a clevis pin. Clevis rod ends have the traditional U-shaped design and a hole around the base. They’re machine-formed with threaded holes for additional security and stability.
Common Questions About Clevis Fasteners
Here are answers to some of the more common questions that we hear about clevises.
What is the purpose of a clevis?
A typical purpose of a clevis is to connect or fasten and secure loads to construction machinery, pickup trucks, and trailers. Clevises can even be used to secure loads to an aircraft.
Is a clevis pin stronger than a bolt?
A pin is stronger than a bolt. For example, a clevis pin fitting an 8mm hole will fill up the entire diameter. Comparatively, an M8 x 1.25 bolt will only have the 6.65mm core diameter, making it the much weaker option.
How strong is a clevis pin?
Clevis pins are exceptionally strong. They can be manufactured in any grade of steel to fit your needs.
What is a clevis end?
While using a clevis pin connection, clevis ends attach to a mounting point, offering seamless connection/disconnection of levers, chains, hooks, and rope. It could also be attached or removed to a fixed mounting point.
Is there a difference between a shackle and a clevis?
The design and appearance of shackles and clevises are very similar, but their purposes tend to differ. However, shackles are generally employed in rigging, lifting, and construction. While clevises are primarily used for farming, towing, and other less demanding applications.
Are clevis pins hardened?
Yes–clevis pins are typically hardened.
What is a Clevis Hook?
Clevis hooks have a clevis and bolt/pin at the base. It might or might not have a snap lock. The clevis is used to fasten the hook to a chain or bracket.
Custom Clevis Fabrication Services
With more than 40 years in the metal fabrication industry, The Federal Group USA is capable of producing high-quality custom clevis fasteners or clevis components. Schedule a time to speak with one of our experienced customer sales engineers if you are interested in learning more about our capabilities and services.