June 6, 2013
PEM® spinning clinch bolts from PennEngineering® install permanently in thin sheet metal, but can spin freely in the sheet. This allows for quick attachment of mating hardware and reduced need for loose fasteners, such as screws and retaining clips or washers, according to the company.
The product line includes Type SCB™ fasteners with an unthreaded neck for axial float, Type SCBJ™ hardware integrating a jacking feature, and Type SCBR™ versions with a self-retracting feature enabling the captive screw to remain retracted when engaged. All permanently install into aluminum or steel sheets as thin as 0.040 in. and can be specified for close centerline-to-edge applications.
The fastener is pressed into a properly sized mounting hole, and squeezing force is applied on the top of the screw head and underside of the sheet. The squeezing action forces the displacer of the screw into the sheet, causing it to reduce the mounting-hole diameter and ultimately capture the screw.
The spinning clinch bolts are available in various lengths and thread sizes from #4-40 through #6-32 and M3 through M4.