My Account
Shopping Cart

ARP 200-8405 Stainless Steel Washers 5/16" Bolt Size

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

200-8405
08/02/2036 9:13 AM
Sale Price

$2.44

In Stock (10+)

delivery box

Usually delivered within 2 days

Authorize Seller Badge
No Hassle Returns

No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

ARP's 200-8405 stainless steel washers are designed for general-purpose applications including accessory mounting, chassis components, and various automotive assemblies. These precision-engineered washers feature excellent corrosion resistance thanks to their stainless steel construction.

Key Features:

  • Designed for 5/16" shank bolts and studs
  • 9/16" outer diameter provides proper load distribution
  • Oversized inner diameter clears most under-bolt head radii
  • Stainless steel construction for superior corrosion resistance
  • Ideal for accessory mounting and chassis applications

Important Note: These washers are engineered for general-purpose use and are not hardened for critical high-stress applications such as cylinder heads, main caps, or connecting rod bolts. For those applications, ARP's hardened washers should be used instead.

ARP is a trusted name in fastener technology, providing quality components for automotive, racing, and performance applications. Each washer meets ARP's strict quality standards for precision and reliability.

Products specifications

Hardened

No

Inside Diameter Chamfer

No

Quantity

Sold individually.

Size (ID/OD)

3/8 / 5/8

Thickness

.063in

Washer Finish

Natural

Washer Inside Diameter (in)

0.375 in.

Washer Inside Diameter (mm)

9.525 mm

Washer Material

Stainless steel

Washer Outside Diameter (in)

0.625 in.

Washer Outside Diameter (mm)

15.875 mm

Washer Thickness (in)

0.063 in.

Washer Thickness (mm)

1.600 mm

i looked for a week to find the best price and autoplicity had the rest beat and they didnt charge me an outragous shipping and handling fee.... will use again...

Very good and easy experience! Items shipped out quickly. Definitely will do future business here.

Site use was easy, and product shipped promptly after ordering. Price was the best I could find, would use this business again.

Autoplicity did a wonderful job, and was definitely the best price. I don't know how they do it, BUT I'll buy more from them. Amazingly swift delivery. GREAT SERVICE !!!!!!

You can tell customer service is important to this company. Not only were the prices lower than other places but they communicate the status of the order and shipping very well. They obviously care what people think. I was suspicious of all the positive comments but decide to try them anyways. Very happy I did and definitely plan on buying from them again.

Utilized customer support for question on particular item. Phone answered immediately, consultant answered questions and I was able to place order immediately. This second purchase was due to the initial experience. Will make future purchases from Autoplicity.

Great Price! Fast Shipping!

fast and easy

Share icon
Return Policy
Returns are easy at Boatplicity

Not happy with a purchase? No problem. We've made returning items as easy as possible. And most purchases can be returned for free for 30 days. Learn more about our Returns Policy