Sturdy Magnesium Water Heater Anode Rod

Protect your water heater with our durable magnesium anode rods, preventing corrosion and extending its lifespan. Enjoy clean, healthy water with ease.


Interior corrosion is a common factor that can significantly reduce the lifespan of water heaters. The presence of harsh minerals in the water can lead to the accumulation and erosion of steel surfaces within the heater tank, especially when exposed to high temperatures.

Magnesium pencil anode rods, also known as soft water anodes, play a crucial role in protecting the internal metal surfaces of water heater tanks from rust through electrochemical reactions. These sacrificial magnesium rods corrode instead of the tank itself, effectively extending the lifespan of the water heater. Regular replacement of anode rods can greatly enhance the durability of the system.

Anode rods for water heaters are typically made of aluminum, magnesium, or zinc. While magnesium anode rods corrode faster than aluminum or zinc rods due to their higher voltage during the sacrificial process, they are gaining popularity due to the potential health benefits of dissolved magnesium in water.

Quality Substrate Material
Our pencil anode rod, made from premium magnesium, meets ASTM B843-AZ31B standards. It features an alloy with Al, Zn, and Mn, 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 traditional cast anodes. This design enables it to provide increased current per unit weight, ensuring robust protection for water heaters, even in challenging electrolyte conditions with higher resistivity.

Uniform Current Distribution
The magnesium pencil anode rod features a continuous steel core throughout its length, offering consistent and effective current distribution for reliable and steady operation.

Easy Replacement
Regularly inspect and replace the anode rod when draining the water heater tank to ensure optimal performance. Typically, replace the rod when corrosion has used up around 75% of its mass. Our pencil anode rod offers up to a two-year lifespan for effective corrosion protection.

Strict Quality Control
Our magnesium anode rods are crafted in compliance with ISO 9001:2015 guidelines, undergoing thorough manufacturing, inspection, and testing under rigorous quality protocols to guarantee top-notch performance.

Customized Configurations
Keeper Anodes warehouse stocks standard sizes listed below, while custom sizes can be requested to meet specific needs.

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”