90° Stainless Steel Drain Through-Hull Fitting (19 mm, 29 mm, 38 mm)

This 90° stainless steel through-hull fitting is built to handle the rigors of marine use while providing a clean look on your boat’s exterior. Unlike plastic or lesser metal fittings, it is crafted from solid AISI 316 stainless steel, which means it can withstand constant exposure to saltwater, UV, and physical impacts without failing or rusting. The fitting consists of a flush outer flange and an integrated elbow pipe that bends at 90 degrees, making it especially useful in situations where straight fittings and hoses would be difficult to accommodate.

With three size options available, you can choose the model that matches your hose and application:

• 19 mm (3/4") size: Great for small bilge pumps, sink drains, or overflow hoses on smaller boats. This size is common for many bilge pump discharge outlets and ensures adequate flow for small volumes of water.
• 29 mm (~1 1/8") size: A mid-range size often used for larger manual bilge pumps or certain deck drain systems. It provides greater flow capacity than 19 mm and fits some medium-duty pump outputs.
• 38 mm (1 1/2") size: Suited for high-capacity draining needs such as main bilge pump outlets on larger boats, or scupper drains that need to evacuate water quickly. The large diameter handles significant water flow, useful for heavy rain drainage or emergency dewatering.

The polished flange of each fitting sits nearly flush against the hull or deck, secured with a nut from the inside. This low-profile design minimizes any snag points on the outside of the hull and contributes to a sleek appearance. Installation is similar for all sizes: drill the appropriate diameter hole, insert the fitting (with a sealant for waterproofing), and tighten the back nut. The hose barb inside is ridged to securely hold your hose with a clamp, ensuring a leak-free connection.

• Bilge pump outlet: These 90° through-hulls are ideal for expelling water from your bilge pump overboard. The elbow allows the hose to turn vertically or horizontally immediately, which is perfect if your pump is in a tight space and you need to route the hose upward or sideways without collapse.
• Cockpit or deck drains: Use the larger size (38 mm) for deck scuppers on powerboats or sailboats where water needs to drain out the side quickly. The all-metal design is reliable for critical drainage points that must not fail.
• Livewell/aerator drain: The medium size (29 mm) can serve for livewell or baitwell drains, routing water from tanks to the outside of the hull without sharp hose bends.
• Engine well or sink drain: The small 19 mm fitting works well for draining an outboard engine well or a small sink on board, keeping appearances neat with its stainless finish that matches other deck hardware.

Selecting a stainless steel through-hull like this ensures you won't have to worry about degradation or leaks over time. It's a solid investment in the safety and longevity of your boat’s plumbing. Whether you're refitting a boat to upgrade plastic through-hulls or specifying hardware for a new build, these 90° stainless fittings provide confidence that your drainage and pump systems will perform reliably year after year.