Attwood 66549-3 Stainless Steel Thru-Hull Fitting, 1-1/8 Inch I.D.

The attwood 66549-3 is a stainless steel barbed thru-hull fitting built for below-waterline plumbing installations such as bilge pump discharge, livewell drains, washdown lines, and raw water intake runs. It is cast from certified enhanced #316 stainless steel for strength and long-term corrosion resistance in a marine environment. All visible surfaces are polished to a mirror finish, then the part is passivated for an additional layer of protection against pitting and rust.

The fitting has a 1-1/8 inch inside diameter and a barbed tail end sized to accept and hold multiple hose clamps for a secure connection. Thick stainless sidewalls resist stress and repeated hose flexing over time, and a channel molded under the flange holds a bead of sealant so the fitting can be bedded and sealed from a single side. Wrench flats or an end notch are provided on the body so one installer can tighten the connection entirely from inside the hull, without needing a second person outside the boat. It is backed by attwood's Lifetime Warranty.

Specifications

• Brand: attwood
• Manufacturer Part Number: 66549-3
• Material: #316 Stainless Steel
• Finish: Polished, passivated mirror finish
• Inside Diameter: 1-1/8 inch
• Thread Outside Diameter: 1-3/8 inch
• Thread Length: 2-3/8 inch
• Thread Type: 1 inch NPSM
• Barb Length: 1-1/4 inch
• Total Length: 3-7/8 inch
• Installation Hole Saw Size: 1-1/4 inch
• Maximum Hull Thickness: 1-3/4 inch
• Weight: 0.8834 pounds
• UPC: 022697665492

Frequently Asked Questions

What is the inside diameter of the attwood 66549-3 thru-hull fitting? The attwood 66549-3 has a 1-1/8 inch inside diameter, sized for hose barb connections in bilge, livewell, washdown, and raw water plumbing runs.

What material is this thru-hull fitting made from? It is cast from certified enhanced #316 stainless steel, then polished to a mirror finish and passivated for additional corrosion resistance.

What size hole saw do I need to install the 66549-3? A 1-1/4 inch hole saw is used to cut the mounting hole for the attwood 66549-3 thru-hull fitting.

What is the maximum hull thickness this fitting will work with? The attwood 66549-3 is rated for hulls up to 1-3/4 inch thick, based on its 2-3/8 inch thread length.

Can one person install this thru-hull fitting alone? Yes. The 66549-3 has wrench flats or an end notch on the body so the fitting can be fully tightened from inside the hull by a single installer.

Does the attwood 66549-3 come with a gasket? Attwood thru-hull fittings in this series are available with a new silicone gasket for sealing against the hull surface.

How is the fitting sealed against the hull? A channel molded under the flange of the 66549-3 holds a bead of sealant, allowing a trouble-free seal to be applied during installation.

What is the total length and thread length of this fitting? The attwood 66549-3 has a total length of 3-7/8 inch and a thread length of 2-3/8 inch, with a 1 inch NPSM thread.

How many hose clamps can be used on the barb end? The 1-1/4 inch barb length on the 66549-3 provides enough room to secure multiple hose clamps for a redundant, leak-resistant connection.

Is the attwood 66549-3 covered by a warranty? Yes, attwood backs this stainless steel thru-hull fitting with a Lifetime Warranty.

What uses is this thru-hull fitting designed for? The 66549-3 is intended for marine plumbing installations such as bilge pump discharge, livewell drains, washdown systems, and water intake lines.

Why choose stainless steel over a plastic thru-hull fitting? The attwood 66549-3 uses #316 stainless steel with thick sidewalls that resist stress and repeated hose flexing, offering longer service life below the waterline than plastic fittings.