New stainless steel pins from PennEngineering can replace screws for attaching thin panels in assemblies. The pins, called PEM TK TackSerts, can securely attach panels of any material to base panels manufactured from common casting materials (such as AZ91D) and plastics (such as ABS and printed circuit boards). The pins eliminate the need for mating threads from tapped holes or inserts and any rework frequently required due to screw cross-threading and driver bit “cam-out.” Patches to prevent fasteners from loosening are also unnecessary.
The pins feature a tapered tip the makes it easier to align panels with base panels, a specially engineered diagonal broaching knurl (instead of threads) that creates a firm interference fit without hole-tolerance issues, and a low-profile head that minimizes protrusions on attached panels.
Pins come in a variety of lengths and can successfully attach sheets ranging in thickness from 0.067 in. (1.7 mm) to 0.185 in. (4.7 mm), depending on pin length. For plastic bases, simple press-in installation without using heat or ultrasonics is performed by preparing properly sized mounting holes in the top sheet and base panel; placing the pin through the hole in the top sheet and into the through or blind mounting hole of the base panel; and then applying sufficient squeezing force using punch and anvil until the head of the pin contacts the top sheet. Pins can even be installed automatically for high-volume jobs.
Detailed specifications, fastener drawings and 3D models, and performance data (Bulletin TK) can be viewed and downloaded for free.