CMP CMC05 Limited Clearance Zinc Shaft Collar Anode 1-1/4" ID Saltwater

The CMP CMC05 is a limited clearance zinc sacrificial shaft collar anode engineered to provide reliable cathodic protection for propeller shafts in tight-clearance installations where standard collar anodes won't fit. Its low-profile, donut-style design makes it the ideal solution when space between the strut, keel, or hull and the propeller is restricted.

Manufactured from a high-purity zinc alloy that meets or exceeds US Military Specification MIL-A-18001K, this anode delivers consistent, predictable sacrificial corrosion performance — protecting your shaft, rudder, and associated hardware from galvanic corrosion in saltwater environments.

Key Features:

• Salt water use only — zinc alloy formula optimized for saltwater and brackish water applications
• Limited clearance design — low-profile collar fits where standard shaft anodes cannot
• Interlocking two-piece halves — split design allows easy installation and removal around the shaft without disassembly
• Stainless steel hardware included — bolt retainers keep fasteners in place for straightforward above or below waterline installation
• Full circular shaft contact — 100% circumferential contact ensures maximum galvanic protection
• Pressure die-cast construction — consistent alloy density and dimensional accuracy
• MIL-A-18001K compliant — alloy manufactured to US Military Specification using high-purity metals

Specifications:

• Inner Diameter (ID): 1-1/4" (32 mm)
• Outer Diameter (OD): 2-1/2" (63 mm)
• Height / Length: 1-1/4" (32 mm)
• Material: Zinc Alloy
• Water Type: Salt Water / Brackish Water Only
• Hardware: Stainless Steel (included)

The CMC05 is part of the Martyr/CMP limited clearance collar anode series and is a direct-fit replacement for propeller shaft corrosion protection where clearance is at a premium. Replace when approximately half of the anode mass has been consumed to maintain effective protection.