ARP Hex Bolt Kits

2011–2025 Subaru Forester / Subaru Impreza / Subaru WRX / Subaru STI 8740 Chromoly Fasteners

Part #: 664-1007

Overview

The ARP Hex Bolt Kits are premium-quality fasteners designed for automotive enthusiasts and professionals who demand the best in strength, durability, and reliability. Crafted from high-grade 8740 chromoly steel and featuring a heat-treated process, these bolts provide a significant upgrade over standard hardware, ensuring your vehicle's critical components are securely fastened under demanding conditions. Whether you're building a performance engine, upgrading suspension components, or securing trailer attachments, these ARP bolts deliver peace of mind and exceptional performance.

Ideal for street, track, or off-road applications, these fasteners are engineered to withstand high stress and harsh environments. The black oxide finish not only enhances corrosion resistance but also provides a sleek, professional appearance. With a tensile strength rated at 180,000 psi, ARP hex bolts offer a substantial safety margin, making them suitable for high-performance builds and heavy-duty use.

Key Features

ARP Hex Bolt Kits incorporate advanced materials and manufacturing techniques to deliver superior strength and reliability. The fasteners are made from 8740 chromoly steel, a material renowned for its excellent toughness and fatigue resistance. Each bolt undergoes a rigorous heat-treatment process to optimize its mechanical properties, ensuring consistent performance even under extreme loads.

• Material: 8740 chromoly steel with black oxide finish for corrosion resistance and a professional look.
• Thread Size: M12 x 1.5, compatible with a wide range of automotive applications.
• Fastener Type: Hex bolt with flanged head for secure tightening and even load distribution.
• Underhead Length: 60mm, designed for optimal engagement and strength.
• Strength Rating: Nominally rated at 180,000 psi tensile strength, providing a substantial safety margin over Grade 8 hardware.
• Heat Treatment: Specially heat-treated to enhance toughness and fatigue life.
• Finish: Black oxide coating for corrosion resistance and aesthetic appeal.
• Application: Suitable for engine assembly, suspension, chassis, and trailer hardware.
• Compatibility: Designed to fit most vehicles requiring M12 x 1.5 fasteners, with a focus on high-performance and heavy-duty use.

Construction & Design

The ARP Hex Bolt Kits are engineered with precision and durability in mind. The use of 8740 chromoly steel ensures these bolts can handle high-stress environments, making them ideal for performance applications. The flanged hex head design allows for easy installation and removal with standard tools, while the 60mm underhead length provides ample thread engagement for secure fastening. The black oxide finish not only enhances corrosion resistance but also reduces glare and provides a sleek appearance suitable for engine bays and chassis components.

Each bolt is manufactured with strict quality control standards, including CNC machining and heat treatment, to ensure consistent dimensions and mechanical properties. This attention to detail results in fasteners that maintain their integrity over many cycles of installation and removal, even in demanding conditions.

Installation & Fitment

Installing the ARP Hex Bolt Kits is straightforward and typically requires standard hand tools. The bolts are designed to thread into existing OEM or aftermarket threaded holes without the need for modifications. Due to their precise manufacturing, they provide a secure fit and consistent torque application. No cutting, drilling, or special tuning is required, making them a hassle-free upgrade for your vehicle’s hardware.

• Simply thread the bolts into the designated holes and tighten to the manufacturer’s recommended torque specifications.
• Ensure proper lubrication or thread locker if specified by your application or build instructions.

What's Included

• Complete set of ARP Hex Bolts (664-1007) with black oxide finish
• Installation instructions (if provided)

Ideal For

• Performance engine builds
• Suspension upgrades
• Chassis reinforcement
• Trailer and heavy-duty hardware
• Enthusiasts seeking high-strength fasteners for demanding applications