CMP CMC04 Limited Clearance Zinc Shaft Anode 1-1/8 Inch

The CMP CMC04 is a limited clearance zinc sacrificial shaft anode designed for cathodic corrosion protection on marine propeller shafts in saltwater environments. With a compact, low-profile design, this anode is ideal for installations where standard collar anodes cannot fit due to tight clearance between the shaft and the hull, strut, or cutless bearing.

Manufactured by CMP Group (Canada Metal Pacific) under the trusted Martyr Anodes brand, the CMC04 is precision die-cast from military-grade zinc alloy conforming to US Military Alloy Specifications. It features interlocking halves for easy underwater installation and full 360-degree shaft contact for maximum corrosion protection.

Key Features:

• Inner Diameter (ID): 1-1/8 inch — fits 1-1/8 inch propeller shafts
• Outer Diameter (OD): 2-1/2 inch
• Length: 1-1/4 inch
• Material: Zinc alloy — designed for saltwater and brackish water use
• Interlocking split-collar design for easy installation and replacement
• Full circular radius contact ensures 100% shaft coverage
• Includes Allen head screw with lock washer and bolt retaining washer
• Bolt retaining washers prevent the anode from falling off during use
• Extra alloy material surrounding the fastener for extended service life
• Manufactured to ISO 9001 Quality Management standards
• US Military Alloy Specification compliant

The CMC04 limited clearance shaft anode is the go-to solution for boaters who need reliable cathodic protection in tight spaces. Sold individually. For fresh water applications, magnesium versions are available; for salt and brackish water, aluminum alternatives are also offered within the CMC series.