ARP 234-5201 Main Cap Fasteners - 4-Bolt Main, 12-Point Head Bolt Kit

The ARP 234-5201 Main Cap Fastener Kit provides the ultimate in strength and reliability for securing main bearing caps in high-performance and competition engines. This 4-bolt main kit features premium 12-point head bolts designed to eliminate main cap walk and fretting while protecting your engine block's threads.

Key Features:

• Manufactured from 8740 chrome moly steel for exceptional strength and durability
• Heat-treated in-house to 180,000-200,000 psi tensile strength
• Precision J-form threads rolled after heat-treat for 1000% stronger fatigue life compared to conventional fasteners
• 12-point head design for improved wrench engagement and torque distribution
• Generous under-head radius reduces stress concentrations
• Hardened parallel-ground washers included for proper load distribution
• Professional-grade quality meeting the exacting standards of competitive engine builders

ARP's proprietary thread rolling process is performed after heat-treating, creating threads that are significantly stronger and more fatigue-resistant than fasteners threaded before heat treatment. The rolled threads also produce a smoother, more precise surface that reduces the likelihood of galling and ensures consistent clamping force. This main cap fastener kit is engineered for engines that demand the highest level of reliability under extreme operating conditions.