ARP 245-4202 Cylinder Head Stud Kit Chrome Moly - 8740 12-Point

The ARP 245-4202 cylinder head stud kit delivers professional-grade fastening performance for high-performance and competition engines. Manufactured from premium 8740 chrome moly steel, these studs are precision-engineered to provide superior clamping force and reliability under extreme conditions.

Premium Materials and Heat Treatment:

Each stud is constructed from aircraft-quality 8740 chrome moly alloy and heat-treated to 200,000 psi tensile strength. ARP's vertical rack heat-treatment process ensures complete and uniform heat penetration throughout each fastener, resulting in consistent material properties and exceptional strength characteristics.

Precision Manufacturing:

Following heat treatment, every stud undergoes centerless grinding through multiple precision cuts to achieve near-perfect concentricity. This exacting process ensures studs are exceptionally straight, allowing cylinder heads and gaskets to align easily during assembly. Threads are rolled after heat treatment rather than before, providing approximately ten times better fatigue resistance compared to pre-heat-treat threading methods.

Key Features:

• Premium 8740 chrome moly steel construction rated at 200,000 psi
• 12-point head design for positive engagement
• Vertical rack heat treatment for uniform strength
• Centerless ground for precise concentricity
• Post-heat-treat thread rolling for superior fatigue strength
• Hardened parallel-ground washers included
• Undercut shorter studs on select applications for equalized stretch
• Wide-area flanged head design eliminates valve train removal for retorquing

Installation Advantages:

Head studs provide superior installation benefits over conventional bolts. Studs should be installed finger-tight in a relaxed state, allowing them to stretch only along the vertical axis when torque is applied to the nut. This eliminates the torsional stress that occurs when bolts are simultaneously twisted and torqued, resulting in more accurate and consistent clamping force. The design also simplifies engine assembly by ensuring proper cylinder head and gasket alignment.

Each kit includes all necessary studs, 12-point nuts, and hardened parallel-ground washers for complete installation. ARP's zero-defect manufacturing standard makes these fasteners the choice of professional engine builders across all forms of motorsports.