GROCO 1-1/2" Bronze High Speed Thru-Hull Fitting w/Nut

The GROCO 1-1/2" Bronze High Speed Thru-Hull Fitting w/Nut is engineered for serious boaters and anglers who demand reliable through-hull plumbing without compromising water flow or vessel performance. Whether you're upgrading raw water cooling systems, baitwell circulation, or livewell aeration, this through-hull fitting handles the job with proven durability. Built to NPSM/NPT combination threads, it integrates seamlessly into existing marine systems while delivering superior flow rates compared to standard thru-hulls—critical when every gallon per minute counts during long days on the water.

Constructed from C83600 bronze, this high-speed fitting resists corrosion in saltwater and freshwater environments where standard steel fasteners fail within a season. The bronze material is non-ferrous, meaning it won't degrade vessel hulls through galvanic action—a critical consideration for fiberglass and aluminum hulls. The fitting's aerodynamic design reduces drag compared to conventional thru-hull configurations, preserving fuel efficiency and handling characteristics. The included nut ensures secure installation, and the 1-1/2" diameter provides substantial flow capacity for engine cooling loops, washdown systems, and live bait applications demanding consistent circulation rates.

Installation suits powerboats, sailboats, commercial fishing vessels, and any watercraft requiring upgraded through-hull plumbing at the 1-1/2" size. The bronze construction and GROCO brand reputation make this fitting a trusted choice for both OEM replacements and system upgrades. Boaters upgrading from undersized or corroded thru-hulls will immediately notice improved cooling system response and more efficient raw water delivery. For applications where flow optimization directly impacts engine longevity and comfort systems (air conditioning, ice makers, baitwell aerators), this fitting pays dividends over years of service.