Fork crown main tube clamping stud and nut and washer, Norton short road holder (set) The Clamping stud is often referred to as a pinch bolt. Two sets required per machine Original part number: F11M2/642; 16164 - Fork crown main tube clamping stud x 1 F11M2/643; 16187 - nut for stud x1 - washer for stud