Overview

The Attwood Marine 7555-3 is a cast bronze garboard drain plug for draining bilge water when the boat is hauled and sealing the drain opening again before launch. It uses a 1/2-inch NPT threaded plug with machined tapered pipe threads, a 3/8-inch neck depth, and a flange that mounts with three countersunk #8 screws.

This is the kind of fitting buyers usually check by thread type, mounting style, and material before ordering. If your boat already uses a 1/2-inch NPT garboard drain and you want a bronze replacement for the hull drain point, this plug gives you a straightforward match without changing the basic setup.

Key features

• Cast bronze body for a drain fitting that stands up well in a wet bilge area and regular exposure to the marine environment
• 1/2-inch NPT plug with machined tapered pipe threads for a tight, watertight fit
• 3/8-inch neck depth for checking fit when replacing an existing garboard drain assembly
• Removable plug nut can be turned with a wrench or pliers during haul-out, storage, or seasonal service
• Flange mounts with three countersunk #8 screws for a flush installation at the hull surface

Compatibility and fit

This plug is for applications that call for a 1/2-inch NPT garboard drain. Before replacing an old fitting, it is worth confirming the thread size at the plug, the number of mounting holes, and the flange footprint already in the hull so the new assembly lines up cleanly.

It is a practical replacement when the original plug no longer seals well, the threads are worn, or the drain body has reached the end of its service life. Boats that are trailered, stored ashore, or hauled regularly for maintenance are the most common match for this type of drain.

Installation and use

The flange fastens with three countersunk #8 screws, and the plug can be removed with common hand tools when the bilge needs to be drained. On a replacement job, the main checks are a sound mounting surface, clean threads, and a drain opening that matches the existing garboard location.

This fits owners who want a simple bronze drain assembly without moving to a different thread type or hardware pattern. It works well on boats where the drain is opened and closed as part of regular haul-out, washdown, or winter storage routines.