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Sea-Dog Line 520740-1 Thru-Hull Fitting 5/8 Inch Polypropylene

Manufacturer

Sea-Dog Line

<p>For over a century, Sea-Dog Line has stood as a cornerstone of the marine hardware industry, delivering innovative solutions that meet the demanding needs of recreational and commercial boaters. Founded in the early 1920s by entrepreneur Hans "Action" Broson Sneve, the company began with a unique sales approach—showcasing marine hardware aboard a 55-foot cruiser that sailed from Alaska to Mexico. This hands-on philosophy continues to shape Sea-Dog's commitment to producing hardware that performs reliably in the harshest saltwater environments.</p><h3>Industry-Leading Marine Hardware Manufacturing</h3><p>Based in Everett, Washington, Sea-Dog Corporation operates a 75,000-square-foot warehouse stocking over 8 million parts and runs an injection molding facility with 16 machines producing more than 17 million components annually. The company's extensive product line spans anchoring systems, deck hardware, electrical components, plumbing fittings, and lighting solutions—all engineered with marine-grade materials like stainless steel, brass, and UV-resistant polymers. Sea-Dog's recognition as a multiple-time NMDA Supplier of the Year underscores the brand's excellence in both product quality and customer service, while their on-staff ABYC-certified marine technician provides invaluable installation and technical support.</p><h3>Premium Marine Components for Every Vessel</h3><p>Sea-Dog's <a href="/7549-sea-dog-line-windshield-washers-wipers-replacement-motors-201195">windshield washers, wipers, and replacement motors</a> deliver crystal-clear visibility during inclement weather, with both manual and electric options featuring corrosion-resistant stainless steel arms and UV-stable blades designed specifically for marine windshield applications. Their <a href="/7549-sea-dog-line-electric-horns-200351">electric horns</a> include the popular MaxBlast line, which passed rigorous 600-hour salt spray testing while meeting US Coast Guard COLREGS and ABYC standards for audible warning devices. For fuel and water system integrity, Sea-Dog's <a href="/7549-sea-dog-line-deck-fills-200307">deck fills</a> provide secure, leak-free access points constructed from durable stainless steel with snap-in designs that resist corrosion in saltwater environments.</p><p>When maneuvering in low-light conditions, Sea-Dog's <a href="/7549-sea-dog-line-docking-lights-200335">docking lights</a> offer bright LED illumination with minimal power draw, featuring injection-molded housings that withstand impacts and temperature extremes. Proper airflow is essential for preventing moisture buildup below deck, and Sea-Dog's <a href="/7549-sea-dog-line-hose-and-cowl-vents-200534">hose and cowl vents</a> deliver reliable ventilation with low-profile designs that include snap-in deck plates for bilge applications or dorade box compatibility for cabin use. Each product reflects Sea-Dog's century-long dedication to manufacturing hardware that recreational and professional mariners can trust, voyage after voyage.</p>

Part Number

520740-1
06/14/2036 8:39 PM
Sale Price

$6.96

In Stock (10+)

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Usually delivered within 2 days

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No Hassle Returns

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Live-in-stock inventory

Fitment guaranteed

Fitment guaranteed

Product Details

The Sea-Dog Line 520740-1 is a 5/8-inch thru-hull fitting designed for above-waterline drainage applications on boats and marine vessels. Constructed of injection-molded polypropylene, this fitting is ideal for salt water use as it is completely impervious to electrolysis and corrosion, providing long-lasting durability in harsh marine environments.

Key Features:

  • 5/8-inch hose barb size for secure hose connection
  • Injection-molded polypropylene construction resists corrosion and electrolysis
  • Designed for above-waterline drainage applications
  • Allows water to pass in or out of the vessel safely
  • Non-metallic material eliminates galvanic corrosion concerns
  • Suitable for saltwater and freshwater marine use

This thru-hull fitting provides a reliable connection point for drainage hoses, cockpit drains, livewell systems, and other above-waterline plumbing applications. The polypropylene material offers excellent chemical resistance and UV stability, making it a dependable choice for marine installations where metal fittings would be prone to corrosion failure.

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Ordered on a Sunday night and technically took 6 business days instead of 3 to 5. Everything looks good so far.

Ordered on Sunday, called on Monday for tracking #, received product on Tuesday, and received tracking # on Wed!! I got the item before Autoplicity got a chance to send me the email with the tracking #. A+++!!!

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