Attwood 5/8 in Composite Thru-Hull Fitting – ATT-68555-1
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You have 30 days to request a return. All sale items are final sale.
5/8 in Composite Thru-Hull Fitting for Marine Plumbing
A reliable, corrosion-resistant thru-hull fitting for marine plumbing applications. Made from composite material, this 5/8-inch fitting offers a lightweight, non-metallic alternative to bronze or stainless steel thru-hulls — ideal for above-waterline installations and applications where weight savings and corrosion resistance are priorities.
The composite construction eliminates galvanic corrosion concerns common with metal fittings, making it a practical choice for freshwater discharge, livewell, and bilge plumbing systems.
Specifications
- Size: 5/8 in
- Material: Composite (non-metallic)
- Application: Marine above-waterline plumbing installations
- Part Number: ATT-68555-1
- SKU: ATT-68555-1
Best Use Cases
- Above-waterline freshwater discharge and livewell plumbing
- Bilge pump discharge fittings on powerboats and sailboats
- Cockpit drain and washdown plumbing where composite material is appropriate
- Replacement thru-hull for existing 5/8 in composite or plastic fittings
Parts Desk Insights
Composite thru-hulls are the go-to for above-waterline plumbing where you want to avoid galvanic corrosion and keep weight down. The 5/8 in size is commonly used for bilge pump discharge and livewell drain lines. If you need a larger opening, the 1-1/8 in Composite Thru-Hull (ATT-68557-1) is the next size up in this family. For below-waterline applications or installations requiring higher strength, consider a stainless steel option such as the 316 SS 1" Thru-Hull or 316 SS 2" Thru-Hull. Always verify the fitting is rated for your specific installation depth and application before installing below the waterline.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.