Nut, 7/16in x 20TPI x 0.4in High, zinc plated. Norton LRH steering head pinch bolt nuts, full size Original part number: B2/643; 13459 - steering head pinch bolt nut [Norton] for stud B2/642 same thread used on 9165 - valve rocker securing nut [Norton 1932-1938?] 11664 - rear brake arm torque nut E3238; A3/103 - crankcase and rear engine plate bolt nut