ARP Fasteners — Head Studs, Rod Bolts & Engine Hardware

What This Brand Covers

ARP, short for Automotive Racing Products, is the industry standard for high-strength engine and driveline fasteners, manufacturing head studs and bolts, main studs, rod bolts, and hardware kits in-house from raw material through heat treating and final inspection. ARP fastener coverage spans nearly every engine platform enthusiasts build, from domestic V8s to import four and six cylinder turbo engines and European performance cars.

Manufacturing and Metallurgy

ARP fasteners are produced using vertically integrated processes including cold heading, machining, heat treating, and thread rolling after heat treat, with signature alloys such as 8740 chromoly, ARP2000, L19, and Custom Age 625+ Custom Age that deliver tensile strength levels far above factory hardware. This process control is why ARP maintains ISO 9001 and AS9100 aerospace certifications.

Head Stud and Main Stud Kits

ARP head stud kits replace factory head bolts with studs that thread into the block and allow the nut to be torqued on a stationary fastener, producing more consistent clamping load across the head gasket. Main stud kits reinforce the block-to-main-cap joint, an upgrade commonly paired with head studs on forced induction and high rpm builds like the Ford 4.6L supercharged Cobra and other modular V8 applications. ARP offers both 8740 chromoly and higher tensile ARP2000 alloy options depending on boost and cylinder pressure targets.

Rod Bolts and Connecting Rod Hardware

ARP rod bolt kits replace stock or aftermarket connecting rod bolts with a fastener rated for the higher rpm and cylinder pressure loads seen in built engines, reducing the risk of rod bolt stretch or failure that can lead to catastrophic engine damage.

Bolt Kits and Hardware for Engine Assembly

Beyond head and main fasteners, ARP produces cam bolt kits for Ford modular V8 camshaft installation, intake manifold bolt kits for HEMI 5.7L and 6.1L aluminum manifolds, header bolt kits for exhaust manifold installation, and a wide range of metric and standard 12 point and hex head bolts and nut kits sold individually or in small packs for general engine assembly and fabrication work.

Platform-Specific Kits

ARP offers dedicated head stud and fastener kits for platforms including the VW/Audi 1.8T, BMC B Series, Renault F4R, and Porsche 3.0L/3.3L crankcase through bolt applications, reflecting the brand's reach well beyond domestic muscle car and truck engines into European and import performance platforms.

Ultra-Torque Assembly Lubricant

ARP Ultra-Torque fastener assembly lubricant is engineered specifically for ARP fasteners to produce repeatable friction values during installation, which is critical for hitting accurate torque specs and consistent clamp load across every stud or bolt in a kit. Most ARP head stud and main stud kits include a small bottle of Ultra-Torque, and it is also sold separately for reuse on future builds.

Top Engine Fastener and Internal Engine Brands

• ARP. Head studs, main studs, rod bolts, and precision fasteners for nearly every engine platform
• Cometic Gasket. MLS head gaskets engineered to pair with ARP head stud clamping loads
• Manley Performance. Forged pistons, rods, and valvetrain components for built engines
• Eagle Specialty Products. Forged connecting rods and crankshafts
• Callies. Billet and forged crankshafts for high output engines
• Clevite. Engine bearings engineered for high load applications
• Fel-Pro. OEM-style gaskets and seals for engine assembly
• Total Seal. Piston ring sets for street and race engines

How to Choose the Correct ARP Fastener Kit

• Confirm the exact engine platform, displacement, and generation before ordering
• Match head stud alloy (8740 chromoly or ARP2000) to your boost and cylinder pressure targets
• Pair head studs with a compatible MLS head gasket rated for the same clamping load
• Check whether the kit includes Ultra-Torque lubricant or if it must be purchased separately
• Confirm thread pitch and length match your block or cylinder head specification
• Review whether main studs are needed alongside head studs for your power level
• Check for any machining or clearance notes specific to your block
• Confirm bolt or stud finish (black oxide or stainless) for your application
• Verify torque specifications provided with the kit match your engine builder's recommendations
• Inspect whether water jacket thread sealant is required for interference-fit stud holes

Common Questions

What is the difference between ARP 8740 chromoly and ARP2000 fasteners?

ARP2000 alloy provides approximately 20 percent higher tensile strength than 8740 chromoly, making it the preferred choice for high-boost applications above 30 psi or engines producing significantly more than stock power, while 8740 chromoly remains a strong and cost-effective option for street performance builds.

Do ARP head studs require a specific head gasket?

ARP head studs work with most quality MLS head gaskets, but the head gasket should be rated for the clamping load and cylinder pressure your build will produce. Pairing ARP studs with a gasket like Cometic Gasket is a common combination on boosted builds.

Why is ARP Ultra-Torque lubricant necessary during installation?

Ultra-Torque produces a consistent, repeatable friction coefficient between the fastener threads and mating surface, which is required to achieve the accurate clamp load specified in ARP's torque charts. Using the wrong lubricant or none at all can result in inconsistent clamping force across the fastener kit.

Can I reuse ARP head studs after removing the cylinder head?

ARP studs can typically be reused as long as they are inspected for damage or stretch and cleaned and relubricated with Ultra-Torque before retorquing, but many engine builders replace studs during a full rebuild as a precaution.

Do ARP fasteners come with installation instructions and torque specs?

Yes, every ARP head stud, main stud, and rod bolt kit includes application-specific torque specifications and installation instructions to guide correct assembly.

Are ARP main studs needed for a stock power level build?

Main studs are primarily recommended for high horsepower, high rpm, or heavily boosted builds where main cap movement becomes a concern. Stock or mildly modified engines typically do not require a main stud upgrade.

What platforms does ARP make head stud kits for?

ARP offers head stud kits for a wide range of platforms including Ford Modular and Coyote, GM LS, HEMI, Subaru EJ, Honda K and B series, VW/Audi turbo four cylinders, Porsche, BMC, and Renault engines, among many others.

How long does shipping take on ARP fastener kits?

Most in-stock ARP orders ship the same day from a US warehouse. Delivery typically arrives in 2 to 5 business days.

Can I buy ARP bolts individually instead of a full kit?

Yes, ARP sells many bolts and nuts in small packs of 5 or 10 for general fabrication and repair work in addition to complete application-specific kits.

What is the return policy on ARP fasteners?

Unused ARP fasteners in original packaging can be returned within 30 days. Kits that have been installed or show signs of use are non-returnable.

Why Buy ARP from Black Ops Auto Works

Black Ops Auto Works stocks 812 ARP SKUs across head, main, rod, and accessory fastener categories with real fitment data, competitive pricing, and support from staff who build engines themselves. Products are filterable by year, make, model, and engine platform to confirm the correct application before ordering.

For focused shopping, browse our Engine, Engine Block, Head Components, Cometic Gasket, Pistons, and Valves and Components collections to complete your engine build.