GROCO thru-hull fittings give you a strong, sealed penetration for intakes, drains, and discharge. Choose bronze or stainless in the size and style your hull needs. Choosing GROCO Thru-Hull Fittings GROCO thru-hull fittings carry water in and out of the hull for engine intake, drains, and discharge, so material and size matter for a safe install. Bronze is the traditional choice for below the waterline because it resists galvanic corrosion, while stainless suits select above waterline uses. Fittings are sized by bore, commonly 1 inch, and come in standard and high speed scoop designs, with high speed shapes reducing drag on faster hulls. Combo NPS and NPT thread fittings mate with standard seacocks and valves. Most include a backing nut...
Bronze Hose Barb Thru-Hull Fitting - 1/2" Features: NPS Thread With Hose Connection C83600 Bronze UL Listed 647B The product is made of high-quality materials and can provide you...
2-1/2" Slotted Hi Speed Thru-Hull with NutFeatures: 2-1/2" NPSM / NPT combination thread C83600 Bronze With Nut Slotted SKU: NVN-111454 MPN: HSSLTH-2000-W UPC:
1-1/2" Slotted Hi Speed Thru-Hull with NutFeatures: 1-1/2" NPSM / NPT combination thread C83600 Bronze With Nut Slotted SKU: NVN-111453 MPN: HSSLTH-1500-W UPC: 742985193673
1-1/4" Slotted Hi Speed Thru-Hull with NutFeatures: 1-1/4" NPSM / NPT combination thread C83600 Bronze With Nut Slotted SKU: NVN-111452 MPN: HSSLTH-1250-W UPC: 742985193666
1" Slotted Hi Speed Thru-Hull with NutFeatures: 1" NPSM / NPT combination thread C83600 Bronze With Nut Slotted SKU: NVN-111451 MPN: HSSLTH-1000-W UPC: 742985193659
3/4" Slotted Hi Speed Thru-Hull with NutFeatures: 3/4" NPSM / NPT combination thread C83600 Bronze With Nut Slotted SKU: NVN-111450 MPN: HSSLTH-750-W UPC: 742985195523
3" Bronze Thru-Hull Fitting with NutHigher flow rates are possible with this 3" GROCO thru-hull fitting than conventional thru-hulls.Features: NPSM / NPT combination thread C83600 Bronze UL listed...
1" Bronze Combo Scoop Thru-Hull w/Nut Features: Designed for increased flow compared to standard Thru Hulls NPSM / NPT combination thread C83600 Bronze Specifications:Thread NPS: 1" Including lock nut diameter...
2" NPS NPT Combo Stainless Steel Thru-Hull Fitting with NutFeatures: NPSM / NPT combination thread #316 Stainless Steel Sizes from 1/2" to 3" UL Listed 647B BSPP and Stainless...
1-1/4" NPS NPT Combo Stainless Steel Thru-Hull Fitting with NutFeatures: NPSM / NPT combination thread #316 Stainless Steel Sizes from 1/2" to 3" UL Listed 647B BSPP and Stainless...
2" Bronze Extra Long High Speed Thru-Hull Fitting w/Nut Features: Designed for increased flow compared to standard Thru Hulls and with less drag Extra Long NPSM / NPT combination thread...
1-1/2" Bronze Extra Long High Speed Thru-Hull Fitting w/Nut Features: Designed for increased flow compared to standard Thru Hulls and with less drag Extra Long NPSM / NPT combination thread...
1" Bronze Extra Long High Speed Thru-Hull Fitting w/Nut Features: Designed for increased flow compared to standard Thru Hulls and with less drag Extra Long NPSM / NPT combination thread...
4" Bronze High Speed Thru-Hull Fitting w/Nut Features: Designed for increased flow compared to standard Thru Hulls and with less drag NPSM / NPT combination thread C83600 Bronze The product...
3" Bronze High Speed Thru-Hull Fitting w/Nut Features: Designed for increased flow compared to standard Thru Hulls and with less drag NPSM / NPT combination thread C83600 Bronze The product...
2-1/2" Bronze High Speed Thru-Hull Fitting w/Nut Features: Designed for increased flow compared to standard Thru Hulls and with less drag NPSM / NPT combination thread C83600 Bronze The product...
2" Stainless Steel Extra Long Thru-Hull Fitting w/Nut Features: Extra long NPSM / NPT combination thread #316 Stainless Steel 2 inch stainless steel lengthened full nut with nut Features:...
2-1/2" Bronze Combo Scoop Thru-Hull w/Nut Features: Designed for increased flow compared to standard Thru Hulls NPSM / NPT combination thread C83600 Bronze Specifications:Thread NPS: 2-1/2" The product is made...
Stainless Steel Hose Barb Thru-Hull Fitting - 2" Features: NPS Thread With Hose Connection #316 Stainless Steel UL Listed 647B Groco's HTH series 2" NPS stainless steel through-hull fittings...
Stainless Steel Hose Barb Thru-Hull Fitting - 1/2" Features: NPS Thread With Hose Connection #316 Stainless Steel UL Listed 647B Groco's HTH series 1/2" NPS stainless steel through-hull fittings...
Bronze Hose Barb Thru-Hull Fitting - 2" Features: NPS Thread With Hose Connection C83600 Bronze UL Listed 647B The product is made of high-quality materials and can provide you...
Bronze Hose Barb Thru-Hull Fitting - 1-1/8" Features: NPS Thread With Hose Connection C83600 Bronze UL Listed 647B The product is made of high-quality materials and can provide you...
GROCO thru-hull fittings give you a strong, sealed penetration for intakes, drains, and discharge. Choose bronze or stainless in the size and style your hull needs.
GROCO thru-hull fittings carry water in and out of the hull for engine intake, drains, and discharge, so material and size matter for a safe install. Bronze is the traditional choice for below the waterline because it resists galvanic corrosion, while stainless suits select above waterline uses. Fittings are sized by bore, commonly 1 inch, and come in standard and high speed scoop designs, with high speed shapes reducing drag on faster hulls. Combo NPS and NPT thread fittings mate with standard seacocks and valves. Most include a backing nut for a secure clamp through the hull. Confirm the size and thread match your seacock and hose before you drill.
Bronze is the traditional choice below the waterline for its corrosion resistance, while stainless suits select above waterline applications. Pick by location.
High speed scoop designs reduce drag and turbulence on faster hulls compared with a standard flush fitting, improving water pickup at speed.
Match the bore size and thread type. GROCO offers combo NPS and NPT thread fittings that connect to standard seacocks and valves.
