ARP M12 x 1.25 12pt Nut Kit (Small Collar)

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...

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...

Automotive hardware kits provide complete sets of fasteners, clips, and retainers for specific repair applications or general-use assortments that cover the most commonly needed sizes for a particular vehicle platform or repair type. A complete hardware kit for a specific job, such as a brake hardware kit with all caliper bolts, slide pins, and pad hardware, ensures every item needed for a professional repair is included in a single purchase rather than requiring multiple individual part searches. General-purpose clip and retainer assortments provide a broad selection of the most common push pin and Christmas tree retainer sizes used across multiple vehicle brands, allowing shops and home mechanics to address most trim and body clip replacements from a single kit. Hardware kits that include both the fasteners and the required lubricants or thread-locking compounds provide a complete solution for time-sensitive repairs. Popular Upgrades Brake caliper bolt and slide pin hardware kits ...