If rivet and blind bolt installation is part of your job, then you are probably familiar with Huck Bolts. Invented by Louis C. Huck in 1944, the Huck Bolt has a unique design and is extremely useful for specific types of applications, especially where vibration is an issue. Today, Huck Bolts are available from Arconic Fastening Systems in different sizes and configurations for a wide range of uses. However, to get the best performance from a Huck Bolt, you need to know how to properly install it.
The Benefits of the Huck Bolt
Threaded fasteners have been around for centuries and are extremely useful for a wide range or applications. The only problem is that threaded fasteners such as nuts and bolts can work loose over time, especially if they are being used for high-stress applications or where continuous vibration is a problem. The Huck Bolt was developed to solve that problem by completely redesigning the bolt as a two-piece fastener that uses metal-on-metal contact to secure it in place as a permanent bond.
The Huck Bolt consists of two pieces: a threaded pin and a collar made of slightly softer material. Huck Bolts are available in different sizes and materials for different applications. The Huck BobTail®, for example, is corrosion-resistant, can be installed using a lightweight tool, and is available in steel, stainless steel, and aluminum. The C50L® is designed for heavy-duty applications, meets or exceeds the ASTM A-325 standards for shear and tensile strength, and is available in steel, stainless steel, or aluminum. The Magna-Grip® is a vibration-resistant grade 2 fastener with a wide grip range available in steel and aluminum. Designed for a broad range of applications, the C6L, C120L, and C150L Huck Bolts feature classic, six-groove fastening and are available in steel, stainless steel, aluminum, and as steel pins with stainless steel heads. Arconic also offers the Hucktainer® steel fastener, designed to be installed with consistent pressure for working with softer materials without crushing them.
When installed, the pin is inserted into one side of the workpiece and the collar is fitted on the opposite side, then tightened using a rivet tool that swages the collar to the pin to form a permanent bond. Huck Bolts come in three basic designs: the Huck Bolt with a pintail that remains after installation, the Huck Bolt without a pintail because it is broken off during installation, and the reinforced-panel Huck Bolt for use with softer materials.
The Huck Bolt Installation Sequence
The basic installation procedure is the same for all Huck Bolt types.
Step one: Determine the right Huck Bolt for the application. You want to choose a Huck Bolt that has the right tensile strength, size, and other properties for the application.
Step two: Fit the Huck Bolt pin in the pre-drilled hole. The pin diameter should match the hole size for a tight fit to prevent lateral movement that could weaken the joint.
Step three: Fit the Huck Bolt collar on the side opposite from the pinhead. The collar fits over the pin and will form a strong, lasting joint when the collar is swaged using a riveting tool.
Step four: Place the nosepiece of the riveting tool over the pintail and into the collar and activate the tool. The pressure applied to the collar simultaneously pulls on the pintail to bring the pieces being joined together and swages the collar to maximize metal-on-metal contact so, unlike a nut and bolt, it cannot work loose. The tensile strength of the Huck Bolt is dictated by the number of grooves that are filled.
Step five: The tool breaks off the pintail and installation is complete.
After you have completed these five steps, a quick visual inspection should tell you whether you have installed the Huck Bolt correctly.
There are some variations to this procedure, depending on the installation and bolt type. For example, some rivet tools will collect the spent pin to minimize hazards and cleanup. Also, some Huck Bolts are designed to leave the pintail intact, so it doesn’t have to be removed. There also are a variety of Huck Bolt tools to choose from, including pneudraulic installations tools, hydraulic installation tools, and battery-operated tools, depending on the application.
If you want to learn more about Huck Bolts, be sure to review our Essential Guide to Lockbolts. We can also help you choose the right tool for any job, and our downloadable e-book Rivet Guns: A Comprehensive Guide to Choosing the Right Tool for Your Job is an excellent place to start. And don’t forget that our blind fastener professionals are always available with expert advice to help you find the right fasteners and tools for any job.