GROCO 2" Bronze Extra Long Thru-Hull Fitting w/Nut

The GROCO 2" Bronze Extra Long Thru-Hull Fitting with Nut (model THXL-2000-W) is a marine-grade through-hull assembly engineered for saltwater vessels requiring extended thread engagement. Crafted from C83600 bronze—an alloy prized for corrosion resistance in harsh marine environments—this fitting handles the demanding applications where standard thru-hull penetrations fall short. The extra-long NPSM/NPT combination thread design accommodates thicker hull structures, composite materials, and reinforced fiberglass common in cruising sailboats, offshore fishing platforms, and commercial vessels.

C83600 bronze delivers superior seawater compatibility compared to standard brass, resisting dezincification and crevice corrosion that can compromise hull integrity over time. The combination NPSM/NPT thread format allows this fitting to work with both National Pipe Straight Mechanical (NPSM) and National Pipe Tapered (NPT) connections, providing flexibility for retrofit installations and new-build applications where thread standards vary. The included nut secures the fitting from inside the hull, creating a watertight seal when paired with appropriate hose clamps or compression fittings.

This 2-inch thru-hull is suited for through-deck seawater intake lines, engine cooling systems, and livewell circulation on larger recreational vessels and commercial platforms. The extended thread length is particularly valuable when upgrading aging hulls with thicker laminate schedules or when installing systems through exterior structures that require maximum mechanical grip. Proper installation requires marine sealant rated for saltwater immersion and compatible hose barbs or NPT adapters sized for the 2-inch bore diameter.