ARP Bolts - Rod Bolts, Head Studs and Main Studs


A large number of connecting rod manufacturers have chosen ARP bolts as standard equipment. They’re proud to advertise their products as being equipped with ARP bolts. And for good reason. The “weak link” in a connecting rod has always been the bolt, and racers know that nobody builds a better bolt than ARP. Forged in-house at ARP using only the finest quality materials Heat-treated using special vertical racks to assure complete 360° penetration Threads rolled after heat-treat to provide up to 10-times longer fatigue strength Precision CNC-machined to exacting specifications Specially designed for optimum reliability in each application.


ARP Bolts - Rod Bolts


It is for good reason that virtually every top professional engine builder relies on ARP Pro Series head studs for their all-out competition powerplants. Simply stated, there’s not a better stud setup on the market today.

For openers, ARP uses a premium grade 8740 alloy that is rated far superior to “aircraft” quality. Then, each stud is placed vertically in special racks and precisely heat-treated to 190,000 psi. This procedure ensures complete heat penetration and the results are far superior to those lesser quality studs from other manufacturers who just dump pieces in a basket and hope for the best.

Following heat-treat, each stud is centerless ground to make it as close to perfectly concentric as possible. This procedure involves about ten very slight cuts and results in an exceptionally straight part. It’s important to note that lesser quality studs are not even centerless ground—the material is thread rolled in bar stock form (mostly before heat-treat, when the material is easier to machine). Because ARP studs are manufactured to such exacting tolerances, you will note that gaskets and cylinder heads literally glide into position and are perfectly aligned—something that won’t happen with inferior quality head studs.

ARP® studs are thread rolled after heat-treat, which gives them about 1000% (that’s ten times) better fatigue strength than those studs that are threaded prior to heat-treat (a very common industry practice). It costs a lot more to do it this way, because it’s tough on tooling, but the results are well worth the extra effort.
You will also note that ARP offers specially undercut studs for several engines. This procedure (done only to the shorter studs) more equalizes the “stretch” of both studs, which makes for a more consistent clamping force—and one that compensates for head gasket compression when the cylinder heads are installed. This helps prevent blown head gaskets, and assures optimum engine sealing!

Premium quality heat-treated 8740 chromemoly steel head stud kits are available for most every domestic and import application. You won’t find a better quality stud on the market from any other source. Look for ARP stamped on each stud as your assurance of quality.



ARP Head Studs





There are many important reasons to use ARP main stud kits, including the elimination of main cap walk and fretting, as well as protecting the threads in your engine block. The studs are manufactured in our own factory using the best materials, processes, designs and engineering. Every ARP main stud kit exceeds the most stringent aerospace specifications.
All ARP Stud kits come complete with hardened parallel-ground washers and aerospace quality nuts. Some applications have provisions for mounting windage trays and have specially designed standoff studs with serrated lock nuts to position the windage tray and lock it securely in place. The studs are manufactured from 8740 chrome moly steel, heat-treated in-house to 190,000 psi tensile strength, and precision J-form threads rolled after heat-treat to create a fastener that has threads 1000% stronger than others. Don’t settle for anything less than the best. Insist on genuine ARP studs…you’ll find the name stamped right on the end!


ARP Main Studs


Owners of 1980-2000 Hondas can obtain vastly improved safety through use of new high strength heat-treated chrome moly wheel studs now available from the industry’s leading manufacturer of racing fasteners, ARP. They are available in both stock length (1.850" underhead) and extended length (2.850") for use with aftermarket wheels. The studs are packaged in 4-pack and 5-pack configurations to suit either 4-lug or 5-lug applications.

The ARP studs are manufactured from 8740 chrome moly steel and heat-treated to a nominal tensile strength of 190,000 psi. Threads are rolled after heat-treat, which significantly improves fatigue strength. ARP studs are engineered to handle both the shock loads (shear) common to drag racing and side loads (elongation) of road course activities. The same material and heat-treat is used in ARP studs used in NHRA and NASCAR competition. Studs are cadmium plated for extra durability


ARP Wheel Studs


It’s difficult to determine the amount of torque required to provide the correct preload and clamp force for an ARP bolt or ARP stud. For example— when tightened, dry uncoated fasteners use up about 95% of the applied torque simply by overcoming the friction between the male and female threads. To ensure that all ARP fasteners provide the optimum level of service, the installed residual stress is calculated and verified experimentally using a superior quality lubricant. It is important to note that the friction coefficients of lubricants vary dramatically, making it difficult to consistently produce the exact amount of stress within the fastener to clamp the components together. That’s why ARP developed an ultra-consistent lubricant and recommend the use of our premium grade ASSEMBLY LUBRICANT or THREAD SEALER in order to precisely duplicate the recommended tightening specifications provided with all ARP® fasteners.

• Premium grade Moly base with rust and corrosion inhibitors.
• Effective lubrication range: -30°F to 750°F.
• Load range: 500,000 psi.
• Other applications: Primary assembly lube for engine components,
press fitting, gear trains and general machinery.
Thread Sealer
• Teflon based w/rust & corrosion inhibitors.
• Effective range: -30° to 550°F.
• Sealant range: 10,000 psi (pressure).
• Application: delivers a flexible leak-proof seal in aluminum,
steel, stainless steel and plastic against coolants, water, gasoline,
natural gas and LPG.
NOTE: These products are formulated for use on fasteners.
Not recommended for use on rotating components.

ARP Fastener Lube Pic