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Martyr Anodes CM821629M Driveshaft Housing Anode for MerCruiser Alpha I Gen II

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

CM821629M
06/03/2036 9:32 AM
Sale Price

$18.73

In Stock (10)

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Product Details

The Martyr Anodes CM821629M is a magnesium driveshaft housing anode specifically designed to provide superior corrosion protection for MerCruiser Alpha I Generation II sterndrive outdrives. This sacrificial anode protects vital metal components from galvanic corrosion by corroding preferentially, extending the life of your expensive drive components.

Key Features:

  • Manufactured from premium mil-spec MIL-A-18001 magnesium alloy for optimal corrosion protection
  • Designed specifically for MerCruiser Alpha I Gen II drives (1991 and newer, serial number 0D469829 and up)
  • Erodes inward for consistent performance and easy visual inspection
  • Magnesium composition ideal for freshwater and brackish water environments
  • Direct replacement for Mercury part number 821629
  • Precision-cast to ensure proper fit and maximum galvanic protection

This plate-style anode mounts to the driveshaft housing and should be replaced when 70% eroded to maintain effective corrosion protection. Martyr Anodes manufactures premium marine anodes using only mil-spec alloys to ensure reliable performance and long service life. Always check propeller clearance after installing new anodes to ensure proper installation.

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Excellent selection, great prices, and fast shipping. I am very satisfied.

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Great just what I wanted.

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So far great!

Very easy

Best price online, love the shipping discount that was offered! I installed the parts yesterday and everything was installed perfectly. Saved me over $400 buy buying my upper control arms here for my 04 Acura TSX. I am gonna bookmark the site to my favori

Great customer service. Prompt shipment and excellent prices. I will defiantly be ordering from them again. Just wish I would have found them sooner!!

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