Wednesday, November 30, 2022
Maritime Propulsion

Posted by November 5, 2014

Self-locking Threads for Stainless Steel Nuts

Unique Shock, Vibration, Temperature-Resistant, Self-Locking Thread Form Offered in Stainless Steel Nuts

For ship repair, maintenance and conversion STANLEY Engineered Fastening now offers its self-locking Spiralock thread form – which the manufacturer said 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.

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 reduce the potential for fatigue failure compared to standard threads, the manufacturer added.

The ship repair, maintenance and conversion industry, concerned about corrosion, 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. The fasteners are used to maintain joint integrity on everything from large diesel engines to highly classified Battleship parts and equipment. Fasteners in the ship industry are frequently subjected to repeated exposure to wash downs, harsh chemicals and salt spray.

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, military and aerospace vehicles, as well as medical implants, artificial limbs and heart pumps.

stainless steelcorrosion protectionharsh chemicals