Self-locking Spiralock thread form


Stanley Engineered Fastening now 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, 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.  

These fasteners are 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.