October 18, 2018 - New PEM® PreTect™ thread masking plugs from PennEngineering® will protect internal threads of self-clinching nuts and standoffs during paint and powder coating processes. The pre-installed silicone masking plugs – supplied already in place – have been designed for self-clinching blind standoffs, thru-hole standoffs, and nuts in thread sizes #4-40 to ¼-20 and M3 to M6. Plugs can be augmented for thru-hole fastener types with a specially engineered stretched polyester film offering thread protection on the side opposite the plug. Plugs and film can be removed easily using a fine tip tool when processes are completed.
All self-clinching fasteners provide permanent and reusable load-bearing threads in metal sheets too thin to be tapped or where extruded or stamped threads would be impractical. Usually installed during the fabrication process – before an assembly would undergo painting or powder coating – self-clinching fasteners become integral components. The new plugs and film ensure that paints or powder coatings will not impact the thread integrity of installed fasteners as assemblies move through production.
The plugs and film can reduce labor requirements by eliminating any need to manually mask fastener threads in advance of coating processes or subsequently clean contaminated threads. They have been engineered to withstand temperatures up to 482ºF and 250ºC and fasteners with the feature can be installed automatically to achieve additional production economies.
