GROCO Bronze Thru-Hull Installation Tool

GROCO Thru-Hull Installation Tool (THT-530) makes installing standard GROCO thru-hull fittings possible for a single installer working alone. It is designed for boaters and installers who want a straightforward way to pull a thru-hull fitting tight against the hull without extra hands.

Slide the thru-hull fitting flanged-end first over the tool, where it stops at the proper step, then tie monofilament to the eye and feed it into the pre-cut hull hole. Apply caulking to the flange, pull the fitting through and against the hull from inside the boat, then thread the monofilament through the locknut or seacock to screw it onto the fitting once it's seated firmly. Browse more options in our mounting and rigging hardware category.

Key Features: Fits GROCO thru-hull fitting sizes 1/2" through 3", enables single-person installation, works with monofilament pull-through method, sold individually.

Frequently Asked Questions

What fitting sizes does this tool work with? GROCO thru-hull fittings from 1/2 inch through 3 inches.

Can this be used by one person? Yes, that's the whole point of the tool: it makes single-installer thru-hull installation possible.

What technique does this tool use? A monofilament pull-through method that seats the fitting firmly against the hull before the locknut or seacock is screwed on.