Bolt cylinder head, front centre, Norton all twins (ea)

Bolt cylinder head and barrel bolt, front centre (short), Norton all twins (ea) 1960? to 1976, ZP 26tpi.   
500cc -600cc use 1; 650cc - 750cc use 4.  Note: No built in washer. MUST be used with a thick washer  (use 16213). If you want the washer built into bolt use D12/973
Original part numbers:
 25313; 067918 - cylinder head and barrel bolt (short)