Captive Fastener Self-Clinching Nut, 1/4-20 X 1, Aluminum Part # FHS-M3.5-18, Self-Clinching Threaded Studs - Type FH/FHS/FHA... Speedball Fabric Screenprinting Ink 6-Color Starter Set They are used to provide load-bearing threads in panels with a minimum sheet thickness of .060 inches. Self-Clinching Flush Mount Body Diameter (Inch): 0.3840 Panel Thickness (Inch): 0.1560 to 0.1860 Unicorp's self-clinching flush mount nuts are installed quickly and easily. FH4-0420-24 Penn Engineering Studs | DB Roberts