ARP 233-3701 Cylinder Head Fasteners Pro Series 12-Point Bolts

The ARP 233-3701 Pro Series cylinder head bolt kit delivers professional-grade clamping force and reliability for high-performance and competition engines. These fasteners are engineered to exceed the demands of serious engine builders who require absolute precision and zero-failure performance.

Pro Series Construction:

• Cold-forged ARP2000 material rated at 200,000 psi tensile strength
• Heat-treated prior to thread rolling for superior fatigue resistance
• 12-point head design for precise torque application
• Wide area flanged head eliminates valve train removal for head retorquing
• Reduced wrenching profile allows clearance for larger diameter valve springs
• Undercut short bolts provide additional stretch to compensate for gasket compression

Precision Manufacturing Process:

Each bolt undergoes vertical rack heat-treating to ensure complete and uniform heat penetration throughout the fastener. Following heat treatment, the bolts are centerless ground through multiple precision cuts to achieve exceptional concentricity and straightness. This exacting process ensures that cylinder heads and gaskets align perfectly during assembly.

Complete Kit Includes:

• Application-specific quantity of Pro Series head bolts
• Hardened parallel-ground washers for even load distribution
• ARP Ultra-Torque assembly lubricant
• Detailed installation instructions with torque specifications

Thread rolling is performed after heat treatment, resulting in approximately 1000% better fatigue strength compared to pre-heat-treat threading methods. The undercut design on shorter bolts helps equalize stretch characteristics across all fasteners, providing more consistent clamping force and reducing the risk of head gasket failure.

Each fastener is stamped with the ARP logo as assurance of quality and authenticity. Pro Series head bolts are the preferred choice of professional engine builders across all forms of motorsports competition.