Audi S4 B9 M11 Upgrade Pro-Series 18.8 cylinder head stud bolt setThis set replaces the original cylinder head bolts with high-strength Pro-Series 18.8 stud bolts. This is necessary for major performance upgrades, as the original cylinder head bolts elongate during operation and the cylinder head can lift off. The Pro-Series 18.8 stud bolts with a tensile strength of 1850 N/mm˛ provide a remedy for this. In addition, these stud bolts do not need to be replaced after disassembly, but can be reused.
Technical details:Part number: P101181610.BRKit contents:16 stud bolts (M11)
16 nuts (M11)
16 washers
Assembly lubricant
Assembly instructions
Tensile strength:Pro-Series 18.8 steel
1850+ N/mm˛ (270,000+ PSI)
High-quality materials and manufacturingThe Pro-Series 18.8 sets are high-strength stud bolts made in Germany. A special steel is used, which has a tensile strength of 1850+ N/mm˛ after tempering. All threads are formed and not cut as is customary in the trade. By rolling the threads, the strength of the tooth flanks can be increased by around 30%. All Pro-Series products are supplied with a nickel coating or optionally with a burnished finish and are therefore protected against corrosion in the long term, even under the toughest conditions.
Easy installation and durabilityPro-Series stud bolts have a hexagon socket drive on the head side for screwing in the stud bolts. Thanks to a cone on the engine block side of the stud, these are not supported on the thread flanks when the nuts are tightened, but in the bore of the thread in the engine block. This support protects the threads during frequent assembly of racing engines. A major advantage of Pro-Series over other manufacturers are the nuts and, if necessary, washers included in the set, as these also have a tensile strength of 1850 N/mm˛.
Application list:Audi S4 B9 354 PS
Made in Germany 
