GROCO 1" Bronze High Speed Thru-Hull Fitting w/Nut

The GROCO 1" Bronze High Speed Thru-Hull Fitting w/Nut is purpose-built for boaters and marine engineers who demand reliable through-hull penetrations without sacrificing flow or adding unnecessary drag to the hull. Whether you're installing a raw water intake for engine cooling, a washdown system, or drain lines on a cruising boat or fishing vessel, this fitting delivers the performance characteristics that experienced water professionals expect. High-speed thru-hull fittings serve a critical role in marine plumbing systems, and choosing the right one directly impacts water flow rates, fuel efficiency, and operational reliability.

Manufactured from C83600 bronze—a corrosion-resistant alloy that withstands saltwater and brackish environments—this fitting combines durability with superior hydrodynamic design. The 1-inch diameter accommodates substantial flow volume while the high-speed geometry minimizes turbulence and reduces drag compared to conventional thru-hull designs, a critical advantage for vessels where every knot of speed and every gallon-per-minute of cooling capacity matters. The NPSM/NPT combination thread accommodates both pipe thread standards, offering installation flexibility whether you're working with schedule 40 pipe or hose adapters with tapered threads.

This fitting excels in demanding applications—commercial fishing boats, offshore cruising sailboats, and high-performance center consoles where cooling efficiency directly affects engine longevity and deck operations depend on robust washdown pressure. The included nut simplifies installation through the hull, and the bronze construction ensures decades of service in harsh marine environments. Installation requires proper sealing practices and through-hull reinforcement, making this fitting ideal for new builds, major refits, or emergency replacements where proven bronze reliability is non-negotiable.