How, Why & Where To Use Self-Clinching Fasteners

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Self - Clinching FAQ

	Does the shape of the self-clinching fastener change during installation?
	No, the fastener does not deform in any way. There is no flaring, crimping, swaging, peening or riveting necessary.
	What holds the fastener in the sheet?
	The squeezing force on the fastener causes the sheet material beneath the head to cold flow into the back-tapered shank or undercut of the fastener, securely locking it in place.
	Do I need special equipment to install self-clinching fasteners?
	No. Self-clinching fasteners are installed using any type of parallel acting press which will squeeze the fastener in place.
	Won't these fasteners fall out, twist out or spin in their mounting holes if I tighten down too hard?
	No. Typical torque-out values are generally quite high compared to the rotational force that will be put on them. In fact, for most quality self-clinching nuts, the screw will fail before the nut rotates in the panel material.
	Can I install a self-clinching fastener with a hammer blow or similar force?
	No, a self-clinching fastener must be installed using a squeezing action. A fast impact installation will not allow sufficient time for the sheet material to cold flow.
	I would like to replace some of the welded fasteners I now use in my stainless steel fabrications. Is there a self-clinching fastener that will go into a stainless steel panel?
	Yes. Self-clinching fasteners for stainless steel applications are available. These fasteners are generally made from a specially hardened stainless steel and will install into sheets up to HRB 88 in hardness.
	When using self-clinching fasteners what are my general panel requirements?
	Generally, there are two basic requirements. First, the panel must be a ductile material softer than the fastener which is going into it. This is why the PEM catalog lists a MAXIMUM panel hardness for each fastener type. Second, the panel must meet the minimum sheet thickness required by the fastener. Some self-clinching fasteners can be installed into sheets as thin as .020" (0.51 mm), but generally .030" (0.76mm) or .040" (1mm) is the minimum thickness necessary.
	Is there a maximum sheet thickness I should be concerned with before specifying self-clinching fasteners?
	Generally, there is no specified maximum sheet thickness limitation. However, because of their special design and function a few fastener types do specify a thickness range which includes a maximum.
	I notice some of the fasteners have a hexagonal shaped head. Do I have to punch a hexagonal mounting hole to install these?
	No. All self-clinching fasteners are installed into a round punched or drilled hole. A hexagonal head will cause the sheet material to cold flow around the head to provide high torque-out resistance. The hex head will be flush in the sheet when installed.
	Can I install these blind, from one side, if I don't have access to both sides of the sheet?
	Generally, you must have access to both sides of the sheet to properly install self-clinching fasteners. However, there are some 1/4" (M6) or larger nuts which can be drawn in from one side using an impact-torque wrench.