Audi 5 Cyl Head stud kit M11 The 5-cylinder bolts are crafted from hardened tool steel, ensuring exceptional durability and strength. These bolts are highly durable, having been lab tested with a breaking point exceeding 1700N/mm2. In addition, unlike most bolts on the market, they do not stretch. This part is essential for engines under high boost pressure/cylinder pressure, as the cylinder head can lift, resulting in a broken head gasket or coolant leakage. However, using these bolts can minimize this risk. These tool steel bolts are made using CNC lathe machines, where the threads are "rolled" instead of cut, making them exceptionally strong. These M11 bolts fit: AAN, ABY, ADU, 3B Torque : 110NM Also available in M12