ARP 155-6021 Cylinder Head Fastener Kit

The ARP 155-6021 is a high-performance cylinder head fastener kit engineered to deliver superior clamping force and reliability in demanding engine applications. Manufactured from ARP's premium 8740 chrome moly steel, these fasteners are designed to secure cylinder heads with consistent, dependable torque retention under extreme combustion pressures and thermal cycling.

Key Features:

• Constructed from 8740 chrome moly steel for exceptional strength and fatigue resistance
• Forged in-house at ARP facilities using proprietary manufacturing processes
• Heat-treated on specialized vertical racks to ensure complete 360-degree heat penetration
• Threads rolled after heat treatment to provide up to 10 times longer fatigue life
• Precision CNC-machined to exacting tolerances for consistent performance
• Each fastener stamped with the ARP name as assurance of quality

Material Properties:

The 8740 chrome moly material used in these fasteners is a quench and temper steel capable of achieving tensile strengths between 180,000 and 210,000 psi. While considered moderate strength by today's standards, 8740 offers excellent toughness and adequate fatigue properties for most racing and high-performance applications when threads are rolled after heat treatment, as is standard ARP practice.

Why Choose ARP Fasteners:

ARP fasteners are the industry standard for engine builders and racers who demand reliability. Testing has demonstrated that ARP fasteners provide up to ten times the fatigue strength of competitor products, making them the trusted choice for applications where failure is not an option. Every component is manufactured to exceed OEM specifications and designed for optimal performance in its specific application.