Audi 2.5L TTRS, RS3 ARP Head Stud Kit L19 Material This Kit was designed for drag racers or street racers, running on high boost engines, that need more clamping force and tensile strength than the ARP2000 Stud Kit can offer. If you are looking for the best option, you've found it, as these are 15% stronger than ARP2000 and have a 55% increase in tensile strength over the OEM torque to Yield (TTY Bolts) !! Due to many “head lifting” issues on Audi engines running in excess of 25 PSI, a stronger stud had to be custom made to meet the demands of today's top engine builders and racers alike. These studs are made from vacuum melted alloy steel with sufficient chromium and carbon to achieve high hardness and superior strength Like most high strength, quench and temper steels - L19 requires special care during manufacturing to avoid hydrogen embrittlement. This material is easily contaminated and subject to stress corrosion. It must be kept well-oiled and not exposed to moisture. Recommended for applications boosting higher than 30 PSI. No Modification to your VW Cylinder Head or Block is required as these are a direct drop-in replacement for the OEM Head Studs. Torque Specification: 90 ft/lbs. Yield Strength: 200-230,000 PSI Tensile Strength: 260,000 PSI Note: The nuts and washers included in this kit still utilize premium grade 8740 alloy as only the stud is subjected increased pressure Each kit includes a complete set of L19 head studs, nuts and ARP Assembly Lubricant. The best choice for racing Audi engines !