ARP 300-6621 Connecting Rod Bolt Kit Super Alloy - ARP3.5 2-Piece

ARP 300-6621 is a premium 2-piece connecting rod bolt kit engineered as a direct replacement for Carrillo, Lentz, and Ferrea connecting rods. Manufactured from ARP3.5 super alloy material, these bolts deliver exceptional strength with tensile ratings of 260,000-280,000 psi and superior fatigue resistance for high-performance and racing applications. This kit does not include washers.

Why ARP Rod Bolts Are Superior:

The connecting rod bolt has traditionally been the weak link in any connecting rod assembly. ARP rod bolts are engineered to provide up to 10 times the fatigue strength of competitor fasteners, making them the preferred choice of professional engine builders and connecting rod manufacturers worldwide. Each bolt is proudly stamped with the ARP name as your assurance of quality and reliability.

ARP3.5 Super Alloy Material:

ARP3.5 (AMS5844) is a high-cobalt nickel-based super alloy originally developed for jet engine and aerospace applications where extreme heat and stress are constant factors. This exotic material offers complete immunity to hydrogen embrittlement and corrosion while delivering tensile strength in the 260,000-280,000 psi range with outstanding fatigue characteristics. ARP3.5 is specifically chosen for connecting rod applications in Formula 1, NASCAR, IRL, and other professional racing series where extremely high loads, elevated RPM, and long-term endurance are critical performance factors.

Key Features:

• Forged in-house at ARP using premium quality materials
• Heat-treated using special vertical racks to ensure complete 360-degree penetration
• Threads rolled after heat-treat to provide up to 10 times longer fatigue life
• Precision CNC-machined to exacting specifications
• Specially designed for optimum reliability in high-performance applications
• Complete resistance to hydrogen embrittlement and atmospheric corrosion
• Superior material grain flow for enhanced strength characteristics

Application Note:

Direct replacement for Carrillo, Lentz, and Ferrea connecting rods. It is critically important to monitor bolt stretch and replace any bolt that has permanently elongated by .0005" or more. Regular inspection ensures continued reliability in high-stress racing environments.

What's Included:

• 2 connecting rod bolts (washers not included)