Screw achieves secure fastening in plastics.
Press Release Summary:
BosScrew(TM) addresses issue of plastic assemblies loosening from plastic creep that dissipates clamp load. Rather than compensating for plastic creep, fastener uses creep to achieve interlocking embedment of threads in material. Once clamp load is applied to assembly, plastic creeps into indentations in threads, creating resistance bumps in material. To loosen, reverse tightening torque must be applied to drive the screw back over bumps and loosen it.
Original Press Release:
New Screw Interlocks with Plastic and Will Not Loosen
The persistent problem of plastic assemblies loosening as a result of the plastic creep that dissipates clamp load has finally been resolved with the development and introduction of the BosScrew(tm) by ITW Shakeproof. Based on extensive tests at the ITW Global Product Development laboratories and corroborated in customer testing, the BosScrew provides as much as 4 times the holding power and a drive-to-strip ratio 66%
better than the leading screws being used in today's plastics. According to its developer, this is not merely a new screw for plastic materials but a new concept in how to achieve a secure fastening in plastics.
Rather than attempting to compensate for plastic creep, the BosScrew uses that creep to achieve an interlocking embedment of the threads in the material. This unique screw has a series of "pressure wells" or indentations along the upper face of the thread circumference. Once clamp load is applied to the assembly, the plastic creeps into the indentations in the threads, creating resistance bumps in the material with valleys in between. To loosen, the crests in the screw thread, between the indentations, must climb over each of these bumps. Reverse tightening torque must actually be applied to drive the screw back over the bumps and loosen it. The resistance to back-out or
loosening is as much as 450% greater than that achieved by the leading fasteners used in plastics today. As the indentations are on the upper face of the screw threads, they are not operative during installation. As the screw is seated, however, the indentations do perform an important torque-robbing function, permitting the safe use of higher installation torques to generate more effective clamp loads.
For more information phone: 708-681-3891; E-mail: bosscrew@shakeproof.com; or write ITW Shakeproof Industrial Products, 2550 S. 27th Avenue, Broadview, IL 60155
