Sturdy Magnesium Anode Rod for Water Heaters

Protect water heaters from corrosion with magnesium anode rods.



One of the leading causes of reduced water heater lifespan is internal corrosion. The minerals in water can corrode steel surfaces, especially under high temperatures, impacting the tank’s integrity.

Magnesium pencil anode rods, also known as soft water anodes, are ideal for safeguarding water heater tanks against rust through electrochemical reactions. By sacrificing themselves through corrosion, these rods protect the tank from degradation, significantly extending the heater’s lifespan with regular replacement.

Anode rods, made of materials like aluminum, magnesium, or zinc, play a crucial role in corrosion prevention. Magnesium rods, despite quicker consumption, are favored for their superior sacrificial properties and potential health benefits from dissolved magnesium in water.

Quality Substrate Material
Our pencil anode rod, crafted from premium magnesium, adheres to the ASTM B843-AZ31B standard. This magnesium alloy includes Al, Zn, and Mn elements, with a focus on minimizing Ni, Fe, and Cu content for optimal performance.

Element ASTM B843 – AZ31B
Aluminum (Al) 2.5 ~ 3.5%
Zinc (Zn) 0.6 ~ 1.4%
Manganese (Mn) 0.2 ~ 1.0%
Silicon (Si) 0.1% Max
Iron (Fe) 0.005% Max
Copper (Cu) 0.01% Max
Cadmium (Cd) 0.04% Max
Nickel (Ni) 0.001% Max
Total Impurities 0.3% Max
Magnesium (Mg) Remainder


High Current Output
Our extruded magnesium anode rod boasts superior surface and length proportions compared to its cross-sectional area, resulting in enhanced current delivery per weight. This feature enables effective water heater protection, even in environments with higher resistivity electrolytes.

Uniform Current Distribution
The magnesium pencil anode rod features a continuous steel core that runs the full length, serving as structural reinforcement. This design promotes consistent and effective current distribution, ensuring reliable and stable performance.

Easy Replacement
Regular inspection and replacement of the anode rod are recommended during water heater maintenance, especially when draining the tank. Ideally, anode replacement is advised when corrosion has depleted around 75% of the rod’s material. Our pencil anode rod is designed to deliver up to two years of effective corrosion protection before replacement may be needed.

Strict Quality Control
Our magnesium anode rods are crafted in compliance with ISO 9001:2015 standards, ensuring meticulous manufacturing, inspection, and testing procedures to uphold top-notch quality and performance.

Customized Configurations
We offer standard sizes in stock at Keeper Anodes warehouse, with the option for custom sizes upon request to meet your specific requirements.

Item No. Rod Diameter Rod Diameter NPT
KA-WHR-M12 Ø0.5″ (Ø12.7 mm) Ø0.13″ (Ø3.4 mm) 1/2”
KA-WHR-M17 Ø0.67″ (Ø17 mm) Ø0.13″ (Ø3.4 mm) 3/4”
KA-WHR-M21 Ø0.84″ (Ø21.3 mm) Ø0.13″ (Ø3.4 mm) 3/4”
KA-WHR-M22 Ø0.9″ (Ø22.9 mm) Ø0.13″ (Ø3.4 mm) 3/4”