20 Pack 5/16-18 Extruded U-Nuts 304 Stainless Steel U Clip Car Clips Fasteners por | jul 28, 202620× 5/16″-18 U-Nuts (Extruded Regular Profile). Style 20 Pcs 5/16″-18 Regular Extruded U Nuts. High Quality Material: 304 Stainless Steel. Interior: Kick Panels, Trim Fasteners. Material: 304 Stainless Steel.