Corundum Rods: The Complete Buyer’s Guide

Looking for a corundum rod? You are in the right place — a corundum rod is simply a round bar made from corundum, the crystalline phase of aluminium oxide (α-Al₂O₃). On this page we explain what corundum rods are, how purity changes their performance, and how to specify the right one for your furnace.

Corundum Rod = Alumina Ceramic Rod

“Corundum rod” and “alumina ceramic rod” are two names for the same material. Corundum is the natural crystalline form of Al₂O₃; when we make a high-purity oxide bar, it is corundum-phase ceramic. So an alumina rod and a corundum rod share identical chemistry and properties — only the wording differs. If your drawing says corundum rod, match it to the equivalent Al₂O₃ purity.

Purity Grades and What They Change

We supply corundum rods in three main purities:

95% Al₂O₃ — economical, good insulation, service to ~1300°C.
99% Al₂O₃ — better insulation and thermal shock resistance, service to ~1500°C.
99.7% Al₂O₃ — high-purity corundum, lowest impurity, service to ~1600°C.

Higher purity means better electrical insulation, lower thermal expansion mismatch, and a higher safe temperature — but also a higher price.

How to Specify a Corundum Rod

When ordering, give us four things: the purity (95% / 99% / 99.7%), the diameter, the length, and the quantity. We can also match an existing drawing or cut stock rods to length. See our alumina ceramic rods for a full sizing table, or open the corundum rod product page to send an inquiry.

Typical Applications

Corundum rods are used as furnace furniture, kiln supports, insulator pins, thermocouple protection tubes, and structural parts in furnaces running up to ~1600°C. Their hardness, wear resistance, and electrical insulation make them a standard choice in ceramic sintering, heat treatment, and laboratory equipment. Browse more in our Al₂O₃ ceramic products category.

Frequently asked questions

What is a corundum rod?

A corundum rod is a solid round bar made from corundum, the crystalline form of aluminium oxide (α-Al2O3). In practice it is the same product as an alumina ceramic rod — high-purity Al2O3. Purity grades such as 95%, 99%, and 99.7% Al2O3 are all corundum-phase rods, with higher purity giving better electrical insulation and a higher service temperature.

What temperature can a corundum rod withstand?

Continuous service temperature depends on purity: 95% Al2O3 rods are typically good to about 1300°C, 99% to about 1500°C, and 99.7% (high-purity) corundum rods to about 1600°C in air. Above those temperatures the ceramic begins to soften, so choose the purity that matches your furnace chamber temperature.

How is the price of a corundum rod calculated?

Four factors set the price: (1) purity — 99.7% costs more than 95%; (2) diameter — larger bars use more material; (3) length — longer bars cost more; and (4) quantity — larger orders get a better unit price. Send your required purity, diameter, length, and quantity and we will quote.

Can corundum rods be customized in size?

Yes. We supply corundum rods in custom diameters, lengths, and tolerances, and can cut or grind them to your drawing. Standard sizes are also kept in stock for fast delivery. Tell us the specification on your drawing and we will match it.

What are corundum rods used for?

They are used as furnace furniture, kiln supports, thermocouple protection tubes, insulator pins, and structural parts in high-temperature furnaces up to ~1600°C. Their high hardness, wear resistance, and electrical insulation make them a common choice in ceramic sintering, heat treatment, and laboratory furnaces.

Need a custom corundum rod? Open the product page and send us your drawing — we quote by purity, diameter, length, and quantity.