Stanley SK58310 Underwater Hydraulic Sinker Drill 1 × 4-1/4 Hex

The Stanley SK58310 Sinker Drill is a professional-grade hydraulic sinker drill designed for demanding underwater drilling operations and heavy-duty utility construction work. Built to withstand harsh environments, this rugged tool is ideal for commercial divers and contractors working in concrete, rock, and masonry applications. It drills holes up to 3″ (75 mm) in diameter and up to 20 ft (6 m) deep, offering powerful performance and reliability in deep or submerged conditions. 

Equipped with a feathering on/off valve for smooth starts and precise control, the SK58310 features a direct-drive rotation motor with adjustable speeds from 0 to 300 RPM and accepts industry-standard 1″ × 4-1/4″ hex drill steel for easy bit changes. An air flush system clears debris from the hole to maintain drilling efficiency and prevent clogging. Designed for versatile use in any position, the drill includes hose whips (couplers sold separately) and durable construction for long service life.