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Sea-Dog Line 520820 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

520820
09/22/2036 7:06 AM
Sale Price

$15.75

In Stock (10+)

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Usually delivered within 2 days

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Fitment guaranteed

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Product Details

The Sea-Dog Line 520820 is a durable thru-hull fitting designed to allow water to pass in or out of a vessel for drainage applications above the waterline. This marine-grade fitting features a robust injection-molded polypropylene body paired with a corrosion-resistant 304 stainless steel cap, providing long-lasting performance in harsh marine environments.

Key Features:

  • Injection-molded polypropylene body for strength and chemical resistance
  • 304 stainless steel stamped cap resists corrosion in saltwater conditions
  • Designed for use with hose connections for above-waterline drainage systems
  • Compact design with multiple connection points for versatile installation
  • Ideal for livewell drains, bilge pump outlets, and scupper applications

Specifications:

  • Dimension A (Overall Length): 1-7/8"
  • Dimension B (Thread Length): 7/8"
  • Dimension C (Cap Diameter): 1-3/4"
  • Dimension D (Flange Diameter): 3-3/8"
  • Dimension E (Body Height): 1-3/16"
  • Dimension F (Hose Barb Diameter): 5/8"

This thru-hull fitting provides a reliable solution for marine plumbing needs, combining the affordability of polypropylene construction with the durability of stainless steel hardware. Perfect for boat builders, marine technicians, and boat owners performing maintenance or upgrades to their vessel's water management systems.

Took a minute to find but then everything went well

Fast shipping works perfectly

Fast and easy

Great

Product arrived well packaged and in a timely fashion. It is good quality , will leave a fitment comment once it is on.

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