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ARP 400-8345 12-Point Metric Cylinder Head Nut

Manufacturer

ARP

<h3>The Gold Standard in Performance Fasteners</h3> <p>When racing enthusiast Gary Holzapfel recognized that fastener failure was causing many engine breakdowns in 1968, he founded Automotive Racing Products (ARP) to solve a critical problem in motorsports. Drawing on his aerospace fastener manufacturing experience, Holzapfel created a company that would revolutionize the performance fastener industry. Today, ARP stands as the world's premier manufacturer of high-strength bolts, studs, nuts, and specialized hardware for racing and high-performance applications.</p> <p>ARP controls all aspects of the manufacturing process in-house, with all operations closely monitored, enabling the company to maintain its reputation for zero-defect quality. Every fastener undergoes forging, heat treatment, thread rolling, and precision finishing at ARP's Southern California facilities, which span over 115,000 square feet. This vertically integrated approach ensures that each component meets exacting standards for strength, fatigue resistance, and reliability under extreme conditions.</p> <h3>Engineered for Championship Performance</h3> <p>ARP's customer roster reads like a who's who of professional motorsports. The product line ranges from quality high-performance OEM replacement parts to exotic specialty hardware for Formula 1, IndyCar, NASCAR and NHRA drag racing and marine applications. The company's fasteners have secured victories in virtually every major racing championship worldwide, from Top Fuel dragsters to Formula One cars, proving their worth under the most demanding conditions imaginable.</p> <p>The brand's <a href="/48-arp-engine-cylinder-head-bolt-set-10306">engine cylinder head bolt sets</a> represent the cornerstone of ARP's catalog, offering engine builders the clamping force and reliability needed to prevent head gasket failure in high-boost and high-compression applications. These precision-engineered fasteners utilize proprietary materials and heat treatments that deliver up to ten times the fatigue strength of conventional bolts, making them essential for any serious performance build.</p> <p>For engine internals, ARP manufactures <a href="/48-arp-engine-connecting-rod-5276">connecting rods</a> designed to withstand extreme cylinder pressures and high RPM loads. Each rod is manufactured to aerospace standards with tight tolerances and superior material properties. Whether you're building a street performance engine or a full competition powerplant, ARP connecting rods provide the strength and consistency that professional engine builders demand.</p> <h3>Complete Fastener Solutions</h3> <p>Beyond engine components, ARP's product range extends throughout the entire vehicle. The company's <a href="/48-arp-wheel-lug-stud-7680">wheel lug studs</a> offer critical safety and performance benefits for racing and high-performance street applications, providing greater clamping force and durability than factory studs. ARP's product line contains thousands of part numbers and has expanded to include virtually every fastener found in an engine and driveline.</p> <p>Individual <a href="/48-arp-engine-cylinder-head-bolt-5308">engine cylinder head bolts</a> are also available for custom applications or specific replacement needs, manufactured to the same exacting standards as complete sets. This flexibility allows builders to source exactly what they need for specialized builds or repairs without compromising on quality.</p> <p>What sets ARP apart is not just the breadth of their catalog, but their willingness to develop custom solutions for unique applications. The company maintains complete R&D capabilities, including metallurgical research, product design, prototype machining, and extensive laboratory testing. This engineering expertise ensures that whether you're installing a simple head stud kit or building a record-setting race engine, ARP fasteners deliver the reliability and performance that professionals trust.</p>

Part Number

400-8345
07/11/2036 5:28 PM
Sale Price

$6.57

In Stock (6)

delivery box

Usually delivered within 2 days

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No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The ARP 400-8345 is a high-strength 12-point metric nut designed for cylinder head fastening applications. Precision-manufactured from 8740 chrome moly steel, this fastener delivers exceptional clamping force and durability for demanding engine builds.

Key Features:

  • 8740 chrome moly steel construction with 180,000 psi tensile strength
  • 12-point design for improved grip and reduced fastener rounding
  • Black oxide finish for corrosion resistance
  • Engineered wall thickness for optimal strength and rigidity
  • Metric threading for precise fitment
  • Meets ARP's rigorous quality standards

ARP fasteners are the gold standard in the performance engine building industry, trusted by professional engine builders and racing teams worldwide. Each nut is manufactured to exacting tolerances to ensure consistent clamping force and reliable performance under extreme conditions.

Products specifications

Fastener Yield Strength (psi)

140,000 psi

Nut Finish

Polished

Nut Material

Stainless steel

Nut Style

12-point

Nylon Insert

No

Quantity

Sold individually.

Self-Locking

No

Size

M10 x 1.50

Socket

12mm

Washers Included

No

Wrench Diameter

12mm

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Shipped and received in quick fashion. Item arrived as expected. Would definitely buy from again!

Product was cheapest I could find and shipping was super fast. Not sure how you could go wrong with them.

no problems

Great price and quick shipping!

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