GROCO Bronze Thru-Hull Fitting Built for Marine Durability

The GROCO HSTHXL-750-W is a marine-grade, high-speed thru-hull fitting made from durable C83600 bronze, designed to minimize drag while ensuring strong flow for intake or discharge on high-performance or planing hulls. It features an extra-long combo thread (NPSM/NPT) to accommodate thick hulls, making it ideal for modern fiberglass or composite constructions. The design induces slightly positive pressure when the vessel is underway, improving flow performance compared to standard thru-hull fittings. The supplied nut allows secure installation, ensuring the fitting stays firmly mounted below the waterline.