The Spiralock self-locking fastener features a 30-degree wedge ramp at the root of the thread. This wedge ramp, which mates with standard 60-degree male thread fasteners, allows the bolt to spin freely relative to female threads until clamp load is applied. The crests of the standard male thread form are drawn tightly against the wedge ramp to eliminate radial clearances and create a continuous spiral line contact along the entire length of the thread engagement. By spreading the clamp force evenly over all engaged threads, this continuous line contact enhances resistance to vibrational loosening, axial-torsional loading, joint fatigue, and temperature extremes. Spiralock nuts, which consist of stainless alloy A-286 and alloy steel, are able to withstand vibration and static load conditions. The nuts withstand even the most severe vibration environments, including high amplitude and sine random testing conducted by the Goddard Space Flight Center. The devices have passed vibration tests in sine and random that were ten times as strong and ten times as long as space shuttle specifications. In addition, Spiralock wire inserts have been tested by the British Aerospace: Naval Warfare Division at 13.6 Hz and tightened to 1,800 pounds of preload. The results indicated that Spiralock wire inserts yield consistent vibration resistant performance with an average preload loss of 15 percent. Testing by the Lawrence Livermore National Laboratory revealed that the devices resist axial-torsional loading, with the first thread of the Spiralock nut supporting 12.5 percent of the total load at the assembly preload of 1,733 lb. and no thread supporting less than 8 percent of the total load. The fastener’s ability to uniformly distribute a load is illustrated by the fact that, at a 1,733-lb. assembly preload, the effective stress away from the points of contact ranges from 10 to 18 ksi and extends completely to the bottom of the nut. Testing by the Massachusetts Institute of Technology indicates that the Spiralock fasteners evenly distribute total bolt load over the engaged threads and resist joint fatigue. In fact, the devices are said to offer 15 to 20 percent better clamp retention than traditional locking adhesives and exhibit excellent temperature resistance. The fasteners can withstand temperatures as high as 1,300°F and maintain torque and joint integrity over extreme temperatures. Spirolock fasteners can be used for a wide range of applications in the automotive, heavy truck, aerospace/military, medical, agriculture, construction, rail, oil drilling, and food processing industries.