Attwood Marine Short Straight Barbed Thru-Hull Fitting, 316 Stainless Steel

Overview

The Attwood Marine Stainless Steel Thru-Hull Short Straight Barbed is a short-length stainless steel thru-hull fitting with a straight barbed hose tail for above-waterline plumbing connections on boats. It is made for installations where a hose needs to pass cleanly through the hull or transom, such as cockpit drains, baitwell drains, livewell plumbing, or other discharge points that sit above the waterline.

The fitting is cast from enhanced 316 stainless steel, with visible surfaces polished to a mirror finish and passivated for added protection in the marine environment. The short body helps in tighter spaces where there is limited room behind the hull, while the barbed end gives the hose a secure gripping surface for clamp installation.

Key features

• Enhanced 316 stainless steel construction helps resist corrosion in wet, salty, and washdown-prone areas.
• Short straight body suits tight behind-panel or transom spaces where a longer thru-hull would be harder to fit.
• Barbed hose tail supports a secure hose connection with marine hose clamps.
• Sealant channel under the flange helps hold bedding compound during installation.
• Silicone gasket adds a clean sealing surface between the flange and hull.
• Wrench flats and an end notch help the installer tighten the fitting from inside the hull.

Variants

This Attwood Marine thru-hull range varies by hose inner diameter, covering 5/8 inch, 3/4 inch, 1 inch, 1-1/8 inch, 1-1/4 inch, and 1-1/2 inch hose sizes. The matching size should be selected based on the hose already installed on the boat or the hose size specified for the drain, livewell, baitwell, or plumbing system being built.

Installation and fit

This fitting is intended for above-waterline use. Before drilling or replacing an existing thru-hull, confirm the hose inner diameter, hull thickness, available clearance behind the mounting surface, and access for tightening the nut and clamps. The polished flange sits on the outside of the hull, while the threaded body and barb pass through to the inside for connection to the hose.

Use a marine sealant suitable for the hull material and follow normal thru-hull bedding practices. The sealant channel under the flange helps keep sealant where it is needed, and the hose should be clamped securely after it is fully seated on the barb.

Use on board

This fitting is a practical match for boat owners replacing plastic thru-hulls with stainless steel hardware, or for builders and refit projects where the visible fitting needs a clean polished finish. It works well in exposed areas such as the transom, cockpit sides, or topsides where the fitting may see spray, sun, and regular washdowns.