Description

Zinc Donut Shaft Anode — 2″ ID x 1-3/8″ x 3-1/2″

Defend your propeller shaft against galvanic corrosion with this zinc donut shaft anode. Engineered as a sacrificial collar, it mounts directly onto the shaft and corrodes preferentially — protecting your shaft, propeller, and underwater running gear from costly electrolytic damage season after season.

Key Features

• High-Purity Zinc Alloy — Provides maximum galvanic protection in salt water and brackish environments; manufactured to MIL-SPEC zinc alloy standards
• Donut / Collar Profile — Slip-on design fits snugly around the shaft for a secure, low-profile installation without restricting propeller clearance
• Precision-Matched Dimensions — 2″ inner diameter x 1-3/8″ width x 3-1/2″ outer diameter; confirm shaft diameter before ordering
• Drop-In Replacement — Direct swap for worn or depleted shaft anodes; inspect annually or when more than 50% consumed
• No Painting Required — Bare zinc surface must remain uncoated to maintain galvanic activity

Specifications

• Material: Zinc alloy (sacrificial)
• Inner Diameter (ID): 2″
• Width: 1-3/8″
• Outer Diameter (OD): 3-1/2″
• Application: Propeller shaft corrosion protection
• Best For: Salt water, brackish water
• SKU: CMT-C09

Installation Notes

Clean the shaft surface thoroughly before fitting. Slide the donut anode onto the shaft and secure with set screws using appropriate stainless hardware. Position as close to the propeller as practical without restricting rotation. Replace when the anode has lost approximately half its original mass. Do not paint anodes — coating blocks galvanic action and renders the anode ineffective.

A properly maintained sacrificial anode is the most cost-effective insurance for your underwater running gear. The CMT-C09 is a reliable, correctly-sized choice for 2″ propeller shafts.