ARP M9 x 1.25 12pt Nut Kit (10 pack)

ARP (Automotive Racing Products) is the world’s premier manufacturer of high-strength engine and driveline fasteners—head studs and bolts, main studs, rod bolts, and more—engineered and manufactured in-house from start to finish for race-proven reliability. With vertically integrated processes that include cold heading, machining, heat-treating, thread rolling after heat treat, and rigorous QA, ARP maintains aerospace-level certifications (ISO 9001 and AS9100) and validates every part for repeatable clamp load and fatigue resistance. Signature alloys such as 8740 chromoly, ARP2000, L19, and Custom Age 625+ deliver ultimate tensile strengths up to the super-alloy range, while ARP Ultra-Torque fastener assembly lubricant helps achieve consistent pre-load during installation. From street performance builds to professional motorsport programs, ARP fasteners provide precise fitment, superior metallurgy, and the durability needed to keep engines together at elevated cylinder pressures and...

ARP head studs replace factory head bolts with precision-machined threaded studs that provide more consistent and repeatable clamping force on the cylinder head gasket. Unlike head bolts that apply torque through both rotational and tensile forces, head studs allow the nut to be torqued concentrically on a stud that is already stationary, producing more even clamping load across the entire head gasket surface. Popular ARP Head Stud Applications ARP head studs are available for a wide range of performance and turbocharged engines including the Subaru EJ series, Honda K series and B series, Mitsubishi 4G63 and 4B11, Honda Civic and Integra, Toyota 2JZ-GTE, Nissan SR20DET and RB series, GM LS series, Ford Coyote and 5.0, and Dodge/Chrysler HEMI applications. ARP offers both 8740 chromoly and ARP2000 alloy head stud kits, with the ARP2000 material providing approximately 20 percent higher tensile strength for high-boost applications above 30 psi. Why are head studs preferred over head b...

This engine parts collection covers oil catch cans, thermostats, thermostat housings, radiator components, coolant accessories, engine covers, fuse box covers, cap covers, throttle bodies, supercharger pulleys, idler pulleys, tensioner pulleys, and engine bay dress-up parts for trucks, SUVs, muscle cars, boosted builds, high-horsepower street cars, and performance vehicles that need better reliability, cooling, airflow, oil control, and under-hood styling. The collection is particularly strong for Dodge Challenger, Charger, Durango, Jeep Grand Cherokee Trackhawk, and Ram TRX platforms running 6.2L Hellcat, 6.4L HEMI, and 5.7L HEMI engines, where oil catch can and cooling upgrades address known OEM weaknesses in the PCV and thermal management systems. Import performance platforms including GM LS-based builds, Chevrolet Camaro, and Corvette applications are also represented through Mishimoto, CSF, and ZPE GripTec product lines. Builders who invest in engine bay organization and reliab...

Engine hardware encompasses the fasteners, studs, bolts, and specialty hardware that hold an engine assembly together under extreme thermal cycling, high cylinder pressures, and the mechanical loads generated during high-performance operation. Factory torque-to-yield head bolts, rod bolts, and main cap bolts are designed for one-time use and lose clamping force after the first engine cycle, which is why performance engine builders replace them with ARP and Dart high-strength fasteners that maintain specified torque values through repeated heat-and-cool cycles and high-load operation. Choosing correct hardware for the application means selecting the appropriate bolt material, thread engagement depth, and torque specification for the exact engine family and power level being built, rather than assuming that generic hardware provides adequate sealing or structural integrity. The difference between a reliable high-output build and one that fails at the first track session often comes do...

Automotive hardware encompasses the fasteners, clips, retainers, and mounting hardware that hold virtually every component on a vehicle in place, from engine bay bolts that endure extreme heat and vibration to interior trim clips that must release cleanly during service without breaking. Quality automotive hardware from brands including ARP, Dorman, and OEM equivalent suppliers provides reliable clamping force and corrosion resistance that cheap hardware does not, reducing the likelihood of seized or stripped fasteners that turn a simple service into a time-consuming repair. For engine and high-stress suspension applications, ARP's heat-treated fasteners provide torque capacity and fatigue resistance that exceed standard hardware grade specifications by a significant margin. For interior, body, and trim applications, OEM-equivalent push pins, clips, and retainers from Dorman provide exact-fit replacements that insert and release correctly without the frustration of incompatible gene...