GROCO 1" Bronze Extra Long Thru-Hull Fitting w/Nut

The GROCO 1" Bronze Extra Long Thru-Hull Fitting with Nut is a marine-grade through-hull penetration designed for serious boaters and vessel operators who demand reliability below the waterline. Whether you're installing raw water intakes, exhaust systems, or through-hull applications on fishing boats, cruisers, or commercial vessels, this extra-long fitting bridges the gap where standard thru-hulls fall short. Built by GROCO—a trusted name in saltwater and freshwater marine hardware—this fitting handles the demanding job of creating watertight seals through hull thicknesses that require extended thread engagement.

Manufactured from C83600 bronze, this thru-hull fitting delivers superior corrosion resistance in both saltwater and freshwater environments—a critical advantage when metal constantly battles exposure to moisture and electrolysis. The extra-long NPSM/NPT combination thread design allows installation through thicker hull materials, fiberglass structures, or custom builds where standard length fittings won't engage enough threads for a secure hold. The included nut ensures you can create a proper seal from both the interior and exterior sides, preventing leaks that could compromise your vessel's integrity during rough seas or extended cruising.

Anglers running through-hull systems for live wells, cooling loops, and sea strainers will appreciate the durability and long service life bronze provides. The 1-inch diameter accommodates moderate-flow applications common on center consoles, cabin cruisers, and fishing vessels. Installation pairs the fitting with appropriate hose clamps and marine sealant, and the dual-thread configuration ensures compatibility across both NPT and NPSM specifications, simplifying sourcing and reducing fitment errors. For anyone replacing aged thru-hulls or upgrading marine systems, GROCO's extra-long design is the professional choice when hull thickness demands maximum engagement.