MATERIALS: The newest PEM® SpotFast® fastener permanently joins metal sheets to PC boards or plastic panels and creates a flush-attachment connection without protrusions on either side. These fasteners offer practical alternatives to riveting or adhesives and their rotational capability extends application potential with the fastener serving as a single flush-mounted pivot point.The steel fasteners (Type SFK) install smooth with the top metal sheet and flush or sub-flush with the bottom panel. When used as a pivot point, the top metal sheet is captivated between the head of the fastener and the lower (non-rotating) panel, which allows the metal sheet to rotate freely.
The fastener’s unique design featuring two separate clinch and knurl joining profiles holds the key. Squeezing the fastener into place using punch and anvil causes a cold-flow of the metal sheet material into the fastener’s clinch profile and a broaching fit of the knurled end into the PC board or plastic panel. The result is permanent and flush attachment of sheet to board or panel.
Standard parts can install with minimal space requirements into metal sheets as thin as .031 inch/0.8mm with hardness of 80 or less on the Rockwell “B” scale. Various head sizes and diameters are available to suit application needs.
Detailed specifications (Bulletin SFK) and free part drawings (PEM CAD Library) for these RoHS-compliant fasteners can be accessed at www.pemnet.com.
- Edited by Liz Taurasi