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Sea-Dog Line 520831 90° Thru-Hull Fitting with Stainless Steel Cap

Manufacturer

Sea-Dog Line

<h3>About Sea-Dog Line</h3><p>Few names in the marine industry carry as much history as <strong>Sea-Dog Line</strong>. Founded in 1923 and headquartered in Everett, Washington, Sea-Dog has spent over a century engineering and supplying dependable hardware for boaters, riggers, and marine professionals. Whether you are outfitting a small fishing boat or a serious offshore vessel, Sea-Dog's expansive catalog — spanning more than 2,400 products — is built around one principle: hardware that holds up when it matters most.</p><h3>A Century of Marine Innovation</h3><p>Sea-Dog Line began as a focused marine rigging and hardware supplier, and over the decades grew into one of the most comprehensive sources for anchoring, docking, boarding, and boat-management equipment in the industry. Their product line has expanded to include antenna accessories, trailer hardware, boat hooks, cabinet and hatch fittings, chain and rigging components, and a wide range of electrical accessories — all engineered to withstand the corrosive, high-stress environment of the marine world.</p><p>What sets Sea-Dog apart is a commitment to manufacturing quality that boat owners can rely on season after season. Their hardware is designed for real-world marine use, meaning saltwater resistance, UV stability, and structural durability are never afterthoughts.</p><h3>Marine Visibility & Windshield Systems</h3><p>One of Sea-Dog's highest-demand product areas is their line of <a href="/7549-sea-dog-line-windshield-washers-wipers-replacement-motors-201195">Windshield Washers, Wipers &amp; Replacement Motors</a>. Maintaining clear visibility on the water is a safety-critical function, and Sea-Dog supplies a broad assortment of wiper blades, washer systems, and complete replacement assemblies designed to fit a wide variety of marine windshield configurations. For boaters who need a direct drive solution, Sea-Dog's dedicated <a href="/7549-sea-dog-line-windshield-wiper-motor-8824">Windshield Wiper Motors</a> offer reliable performance in wet, high-vibration marine environments — a category where component quality directly affects on-water safety.</p><h3>Cockpit Comfort & Functionality</h3><p>Beyond hardware and visibility systems, Sea-Dog also brings practical innovation to the helm and cockpit with their <a href="/7549-sea-dog-line-cockpit-fillet-tables-200274">Cockpit &amp; Fillet Tables</a>. These tables are designed to maximize usable space aboard, whether you are prepping a catch, serving guests, or simply organizing gear. Sea-Dog's tables reflect the same build philosophy as all their hardware: functional, durable, and thoughtfully designed for the marine setting.</p><h3>Why Boaters Trust Sea-Dog Line</h3><ul style="list-style:disc"><li>Over 100 years of marine hardware expertise dating back to 1923</li><li>Headquarters in Everett, Washington, with a deep understanding of Pacific Northwest and offshore boating demands</li><li>A catalog of more than 2,400 products spanning virtually every marine hardware category</li><li>Products engineered for saltwater, UV exposure, and the vibration of on-water use</li><li>Trusted by recreational boaters, commercial operators, and marine riggers alike</li></ul><p>From rigging essentials to cockpit accessories and windshield systems, Sea-Dog Line remains one of the most complete and dependable marine hardware brands available today. Explore their full product range and find the right Sea-Dog components for your vessel.</p>

Part Number

520831
09/14/2036 1:45 PM
Sale Price

$18.50

In Stock (10+)

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Usually delivered within 2 days

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No Hassle Returns

Live-in-stock inventory

Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sea-Dog Line 520831 is a 90-degree thru-hull fitting designed to allow controlled water passage in or out of a vessel above the waterline. This marine-grade fitting is ideal for drainage applications, bilge pump outlets, livewell systems, and other onboard plumbing needs.

Key Features:

  • Injection-molded polypropylene body for excellent corrosion resistance and durability
  • 304 stainless steel cap provides superior strength and marine-grade corrosion protection
  • 90-degree angle configuration for efficient hose routing in tight spaces
  • Designed for use with marine hose for above-waterline drainage applications
  • Threaded design allows secure installation through hull or bulkhead

Specifications:

  • Dimension A (Overall Height): 1-7/8"
  • Dimension B (Thread Length): 7/8"
  • Dimension C (Cap Diameter): 1-13/16"
  • Dimension D (Base Flange): 3-7/16"
  • Dimension E (Outlet Length): 1-15/16"
  • Dimension F (Hose Barb): 3/4" for standard marine hose connection

This fitting combines the chemical resistance and lightweight properties of polypropylene with the strength and corrosion resistance of stainless steel, making it an excellent choice for marine drainage systems, bait tank plumbing, and other wet applications on boats, yachts, and personal watercraft.

We were very pleased with the quality of the bumper we purchased and the customer service was superb. We received both the bumper and kit within 3 days. This is the first time we ordered from Dirt Everywhere and we would not hesitate to order from them again. Thank You for the great service !!!

great and easy

great price and availability

Easy and very competitive pricing

It was fast service

Good prices and the tires were fresh. No complaints or issues.

Easy to purchase, received my product rather quickly and on time.

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