Fab-Lok is a carbon or stainless steel threaded machine screw mechanically joined to a slotted rivet sleeve. The sleeve is aluminum. A 1/2″ OD EPDM Composition washer provides a positive seal.
Fab-Lok is inserted into a 5/16″ hole (hole size is not critical) and is installed with a power driver equipped with a Fab-Lok holding sleeve. As the screw turns, the sleeve is drawn up into four clamping tines which provide the holding power.