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Martyr Anodes CM55989A Aluminum Nut Anode for Mercury Mercruiser Alpha Bravo Sterndrive

Manufacturer

Martyr Anodes

<h3>About Martyr Anodes</h3><p>When it comes to defending a vessel against galvanic corrosion, few names carry the authority of <strong>Martyr Anodes</strong>. A flagship brand within the <strong>CMP Group</strong>, Martyr has its roots in foundry operations that date back to the early 1900s in Vancouver, BC, growing from a local manufacturer into a globally recognized leader in marine cathodic protection. Today, the brand supplies boaters, commercial operators, and marine professionals worldwide with sacrificial anodes engineered to guard hulls, propellers, rudders, shafts, engines, and other submerged components from the relentless effects of corrosion.</p><h3>Three Alloys, Every Water Type</h3><p>What sets Martyr apart from competing anode manufacturers is its position as the only brand to offer all three protective alloys — zinc, aluminum, and magnesium — under a single product line. This matters because the correct alloy depends entirely on the water environment a vessel operates in. Zinc anodes are the classic choice for aggressive saltwater conditions, while aluminum anodes are preferred for saltwater and brackish environments, offering superior corrosion resistance with a reduced environmental footprint. Magnesium anodes are the go-to solution for freshwater use, delivering effective sacrificial protection without degrading too quickly. Whatever the operating environment, Martyr has an engineered solution to match.</p><h3>Military-Grade Manufacturing Standards</h3><p>Martyr does not cut corners on metallurgy. Every anode is pressure die-cast and manufactured to meet or exceed <strong>U.S. Military alloy specifications</strong>, using only high-purity metals. Each alloy batch is lab-tested with full certification and traceability available upon request. This rigorous quality management — operating under an ISO 9001 framework — ensures that each anode delivers consistent, long-lasting galvanic performance across a wide range of marine environments, from recreational pleasure craft to commercial vessels and naval applications.</p><h3>Anode Kits for Simplified Protection</h3><p>For boaters who want a complete, hassle-free maintenance solution, Martyr&rsquo;s <a href="/7452-martyr-anodes-anode-kits-200102">Anode Kits</a> offer pre-packaged sets engineered for specific engine models and boat types. Compatible with major marine engine brands including Yamaha, Mercury, Volvo, and MerCruiser, these kits take the guesswork out of corrosion protection and ensure every critical system receives optimal coverage in a single purchase.</p><h3>Sustainability at the Core</h3><p>Martyr and the CMP Group have made environmental stewardship a cornerstone of their mission. Traditional zinc anodes can contain cadmium, a metal that poses risks to aquatic ecosystems. Martyr actively advocates for the adoption of aluminum and magnesium alternatives that deliver equal or superior protection while minimizing harm to marine environments — embodying the brand&rsquo;s philosophy of &ldquo;Protect your boat, protect our waters.&rdquo; With over 1,000 anode types available and a catalog that fits virtually every major marine engine and boat model, Martyr remains one of the most comprehensive and trusted sources for marine corrosion protection in the world.</p>

Part Number

CM55989A
06/03/2036 9:38 AM
Sale Price

$5.04

In Stock (10+)

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Usually delivered within 2 days

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Product Details

The Martyr CM55989A is a premium aluminum sacrificial anode designed specifically for Mercury and Mercruiser stern drives. This hexagonal nut-style anode provides critical corrosion protection for aluminum stern drive components by sacrificing itself to prevent galvanic corrosion damage to the outdrive housing and internal components.

Key Features:

  • Hexagonal design (1-1/4" hex) for easy installation and removal with standard tools
  • Aluminum alloy construction ideal for brackish water and saltwater applications
  • Manufactured to meet or exceed U.S. Military specifications for marine anodes
  • Mounts to Alpha One gimbal housing mounting bolts or transom plate
  • Replaces Mercury OEM part numbers 55989A3, 55989A4, 55989A9, 55989Q9, 55989T9

Compatibility: For use with MerCruiser MC-I, R, MR, Alpha One (including Gen I and Gen II), and Bravo I, II, III stern drive outdrives. Commonly used on 1983-1990 Alpha One drives and later models. Typically sold in pairs for complete gimbal housing protection.

Specifications:

  • Dimensions: 1-1/4" hex x 1-5/16" height
  • Mounting hole: 1/2" NC thread
  • Weight: Approximately 0.26-0.30 lbs
  • Material: Aluminum alloy

Installation Note: Always check propeller clearance after installing new trim tab or gimbal anodes to ensure the anode does not interfere with propeller function. Inspect anodes periodically and replace when showing signs of corrosion, pitting, or when more than 50% depleted.

Part of the comprehensive Martyr Anodes line from Canada Metal (Pacific) Ltd., recognized worldwide as premium marine corrosion protection products. Martyr anodes are chemically tested for consistency and proven to deliver exceptional efficiency in protecting your valuable marine investment.

Products specifications

Description

Alpha Gimbal HSG

Material

Aluminum

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