STANLEY® Engineered Fastening offers its unique self-locking Spiralock® thread form – which is highly resistant to shock, vibration, and temperature induced loosening – in a full range of corrosion-resistant, stainless steel, fractional and metric hex flange nuts. These are available with same-day shipping from inventory stock.

Proven in thousands of applications, Spiralock® threaded nuts accept standard male fasteners, and eliminate the need for other locking devices, minimize galling since it is free spinning until clamp load is applied, and substantially reduce the potential for fatigue failure compared to standard threads.


Any industry concerned about corrosion such as food service, medical, pharmaceutical, marine, transportation, aerospace, and industrial processing will benefit from the corrosion protection delivered by the nuts’ Grade 316 austenitic stainless steel composition, which can be used instead of lower grades of stainless steel. Used to maintain joint integrity on everything from food-processing equipment, chemical mixing, high-velocity pumps, and compressors to vehicles on road and off road, fasteners in industries like these are frequently subjected to repeated exposure to wash downs, harsh chemicals, salt spray, and even road de-icing conditions.

The Spiralock® thread form solves thread loosening and joint integrity issues by changing the physics of how the threads interact. In traditional 60° threads, the gap between the upper edges of the male and female threads can lead to shock, vibration, or temperature-caused thread loosening. Stress concentration and fatigue at the first few engaged threads is also a problem, particularly with softer metals. The unique profile of Spiralock® threads closes the gap that causes loosening, improving the integrity and reliability of threaded joints.

For more than 35 years, the Spiralock® thread form has been used in extreme fastening applications where joint failure or loosening is not an option: from the main engines of NASA’s Space Shuttle, the Saturn Cassini orbiter, and Titan Huygens probe to deep-sea oil rigs and military and aerospace vehicles, as well as medical implants, artificial limbs, and heart-pumps.

For detailed test data, including comparative graphics, loading characteristics, or photoelastic analysis/load vector comparison animation, visit the Spiralock® pagecontact us, or call (800) 521-2688.

May 29, 2014
Tagged:  Company News