Martyr Zinc Engine Pencil Anode, 1/2" x 2", 3/8-16 Thread – Replacement Zinc Only [CMEZ1]

Replacement zinc pencil anode for engine cooling systems, heat exchangers, oil coolers and aftercoolers. The CMEZ1 is the zinc only — it threads into the brass plug you already have, so you don't need to buy a new plug every time you change zincs.

Pencil zincs sacrifice themselves to protect the more valuable metals in your raw-water cooling system from galvanic corrosion. Check them regularly and replace when about half the zinc is gone. A pencil that's eaten down to nothing means your heat exchanger is the next thing being consumed.

Specifications

• Brand: Martyr Anodes
• Part number: CMEZ1
• Diameter: 1/2"
• Length: 2"
• Thread: 3/8-16 UNC (threads into the plug)
• Material: Zinc, die-cast to US military alloy specification
• For use in salt water
• UPC: 628309103392

Fitment

• Fits the brass plug from the Martyr CME1 complete pencil anode (1/2" x 2", 3/8" NPT plug).
• Need the plug too? Order the CME1 complete anode instead.
• Always match diameter, length and thread to the pencil you're replacing — a pencil that's too long can block coolant passages.

Why zinc for pencil anodes

Zinc is the standard for engine pencil anodes and what most engine manufacturers specify. Aluminum pencils are prone to breaking off at the neck, and the broken piece can end up lodged in coolant passages.

Install tips

• Close the raw-water seacock before removing the plug.
• Clean the threads on the plug and the zinc so they make good metal-to-metal contact. Don't use thread sealant or tape between the zinc and the plug — it can insulate the zinc and stop it working.
• Thread the new zinc in snug, reinstall the plug, open the seacock and check for leaks after starting the engine.