PEM® SpotFast® self-clinching fasteners from PennEngineering®, Danboro, PA, enable two sheets to be joined permanently in a flush-attachment connection without protrusions on either side. These alternatives to riveting or spot welding provide a means to attach two metal sheets too thin to weld, fasten sheets of unequal thicknesses, join dissimilar metals, attach ultra-thin metal sections, or join metal sheets to PCB or plastic panels. The fasteners install smooth with the top sheet, and flush or sub-flush with the bottom sheet. The product family includes Type SF steel fasteners for metal-to-metal attachment, Type SFP precipitation-hardened stainless steel fasteners for installation into stainless sheets where corrosion resistance may be required, Type SFW steel fasteners with supplied wave washer for metal-to-metal single-point hinging applications, and Type SFK steel fasteners featuring two separate joining profiles for attachment of metal sheets to PCB or plastic panels. Standard parts in various head diameters and sizes can be installed in aluminum or steel sheets as thin as 0.030" (0.8mm).