From Stanley Engineered Fastening - Spiralock
For engineers combating vibrational loosening, axial-torsional loading, joint fatigue, and ther mal extremes, conventional fastening methods involving standard 60 degree threads have posed design limitations for too long and proven solutions, backed by test data, have been relatively nonexistent.
Fortunately today, engineers are successfully attacking these problems with an innovative self-locking fastener called Spiralock, whose effectiveness has been validated in published test studies at leading institutions including MIT, the Goddard Space Flight Center, Lawrence Livermore National Laboratory, and British Aerospace, as well as at noted corporations such as Mack Truck and Dana Corporation.
With the standard 60 degree thread form, the gap between the crest of the male and female threads can lead to vibration-induced thread loosening. Stress concentration and fatigue risk at the first few engaged threads is also a problem due to substantial surface contact. Because the standard thread form is axially loaded, there's an increased probability of shear, especially in soft metals. And temperature extremes can expand or contract surfaces and materials, potentially compromising joint integrity.
Products & Services
Locknuts are a type of prevailing-torque fastener that resists loosening under vibration and torque. They differ from standard nuts because they typically have friction-increasing bearing surfaces (e.g., pitted grooves on flanges) or special internal thread-geometries.
Captive fasteners are designed for permanent retention within their target assembly or housing, often even upon servicing, providing a secure joint and avoiding loss or damage that might be caused by a loose part.
Threaded inserts are blocks of material with a threaded hole that are pressed or molded into a part, usually made of a different material.
Nuts are a type of hardware fastener with a tapped inner diameter. They are used with a mating threaded bolt or rod to secure components. There are many sizes and varieties of nuts; each with a particular fastening purpose. Some nuts can be applied without tools, and others may have special designs to prevent the nut from loosening.
Topics of Interest
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