Nut-and-bolt fastener resists vibrations and fatigue

Sept. 21, 2012
Nut-and-bolt fastener resists vibrations and fatigue

The new Huck 360 nut and bolt from Alcoa Fastening Systems, Waco, Tex., resists vibrations and doesn’t loosen regardless of the vibrations or environment. It can also be installed quickly using standard tooling.

Key to the fastener’s vibration resistance are nut threads that are softer and thicker than the bolt threads. So when the nut is tightened on the bolt, the bolt threads become embedded in the nut threads, eliminating any gaps between the nut and pressure flank and crest of the bolt thread. This prevents movement of the nut, which can lead to loosening, and lets the fastener absorb high spike loads.

The bolt threads are also not as deep as standard threads, resulting in 18% more crosssectional area than conventional bolts. And the radius of the bolt thread’s root is up to three times larger than those on most other bolts. These two factors give the Huck 360 up to five times the fatigue strength of conventional bolts.

The nut is designed to quickly spin onto the bolt without tools, although a standard wrench is needed to apply the fastening torque. In studies, the bolts install in one-third the time needed for conventional locknuts. The fastener can be removed with conventional tools.

The nut is dyed red for easy identification.

The bolts come in Imperial (‡3/8ˆ to 1 3‡/8ˆ-in.) and metric (12 to 36-mm) diameters, and have tensile strengths that meet or exceed Grade 8 and Class 10.9 requirements.

© 2012 Penton Media, Inc.

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