The Newest Developments in Self Locking Threaded Fasteners

For manufacturing engineers hoping to improve their products through better self locking fasteners, the immediate future looks quite promising. Competitive advantages can now be achieved by way of the reduced product weight and heightened joint strength that the latest generation of self locking threaded fasteners enables.

"Across a broad range of industries—including automotive, aerospace, medical implant and devices, heavy truck, power generation, household durable goods, weapons, material handling, and construction equipment—engineers have perennially faced the challenge of fashioning stronger unions without adding excess bulk," notes James P. Gillis, Executive Vice President and Chief Operating Officer at Spiralock Corporation. "Newly developed technologies within the thread locking industry have arrived to meet this challenge so that products hold up better under excessive environmental stresses, without compromising the reusability of self locking threaded fasteners or adding excess weight."

Spiralock is a Madison Heights, Michigan-based developer and manufacturer of self locking threaded fasteners, with roots dating back to 1927. The company is best known for its proven "wedge ramp" design that incorporates a unique 30-degree wedge ramp at the root of the thread which mates with standard 60-degree male fasteners. The continuous-line contact of this design spreads the clamp force evenly over all engaged threads, thus improving resistance to vibration, axial-torsion loading, material fatigue and temperature extremes, while still enabling re-usability up to 50 times.

"To provide even greater options to design and manufacturing engineers, the company is launching a new V-band clamp nut for use in high temperature exhaust applications," explains Gillis. "This nut design has extra thread length and load distribution to help eliminate the galling problem commonly encountered because of the long run-down on bolts used to secure manifolds. The payoff is improved fatigue performance, yet unlimited reuse of the self locking fasteners when work needs to be performed on the head."

Gillis also describes a new style of wire-thread insert, called the Spiralock Drive Notch (TM) Insert, that eliminates installation tangs. Such wire thread inserts are increasingly favored by engine manufacturers and aerospace companies for joining soft materials such as magnesium or aluminum.

Also new on the scene are thin walled nuts, which provide weight savings as well as better balancing normally associated with the self-centering aspect of the Spiralock thread locking design. These nuts excel in high-heat, high-rpm turbocharger applications, such as found in performance automobiles and turboprop applications. In both cases, weight reduction is important.

In providing a glimpse into the future, Gillis revealed that, "We have many projects under development to solve a greater number of specific threaded joint applications: a nut that will free-spin onto a bolt and still have enough prevailing torque to prevent it from coming off; self locking threaded fasteners for soft joints such as a gasket; and a tamper-proof nut for more permanent applications."

Given such improvements in thread locking technology, manufacturers can look forward to greater opportunities to design lighter-weight products without sacrificing joint integrity. Further research into providing self locking threaded fasteners with highly-focused application specificity promises to provide solutions well beyond the immediate horizon.


Kate Turowska
Spiralock Corporation
25235 Dequindre Road
Madison Heights, MI 48071
Phone: (248) 543-7800
Fax: (248) 543-1403
KTurowska@spiralock.com
http://www.spiralock.com