Groco (Gross Mechanical Laboratories)

A Century of Marine Hardware Innovation

Since 1918, Groco—formally known as Gross Mechanical Laboratories—has earned its reputation as one of America's most respected manufacturers of underwater marine hardware. Founded in Baltimore by inventor Angus Roy Gross, Sr., the company began during the industrial boom when both marine and automotive industries were expanding rapidly. While Gross held numerous patents for inventions ranging from automobile taillights to blow torches, the company made a decisive pivot to focus exclusively on the marine industry in the late 1920s, a decision that would define its legacy for the next century.

Precision Engineering for Marine Environments

What sets Groco apart in the marine hardware industry is their unwavering commitment to quality materials and precision manufacturing. Operating from their Stevensville, Maryland facility, this third-generation family-owned business specializes in bronze and stainless steel components designed specifically to withstand the harsh conditions of saltwater environments. Their product line encompasses critical underwater hardware including seacocks, ball valves, raw water strainers, thru-hull fittings, water pressure systems, and various pumping solutions. Each component is engineered to provide reliable performance where failure simply isn't an option.

American Manufacturing Excellence

Groco's evolution from manual machining equipment to state-of-the-art CNC machining technology demonstrates their dedication to continuous improvement while maintaining traditional American manufacturing values. Their bronze construction products are particularly notable for their corrosion resistance and longevity, while their #316 stainless steel offerings provide metallurgical compatibility with both bronze and aluminum components without the unsightly green oxidation common to lesser materials. For aluminum hull vessels, Groco also produces weldable #319 aluminum hull scoops.

Trusted by Professionals and Boat Builders

The company's reputation for exceptional construction quality and meticulous design detail has made them a preferred choice for OEM boat builders and shipyards worldwide. Groco's innovative products include their patented E-Valve system, which allows remote electronic control of seacocks from the helm—eliminating trips to the engine room and encouraging regular valve exercise for improved reliability. Their raw water strainers feature unique design elements like magnifying inspection caps and tool-free removal systems that simplify maintenance and reduce downtime.

Whether you're maintaining a recreational vessel or specifying components for commercial marine applications, Groco represents over a century of proven reliability. Their commitment to innovative design, superior materials, and sound construction continues to make them the choice for boaters who demand hardware that's truly a cut above the rest.