What Are Welding Rods Made Of?

Welding rods have a metal core wrapped in a coating of welding flux and ceramic, metallic and chemical compounds. The type of coating and core depend on the metal you're welding.

Anatomy of Welding Rods

Welding rod cores' metals blend with the metal you're welding. The core, wrapped in a flux coating to make the welding current flow evenly, improves the blending of rod and welded metal---strengthening, cooling and stabilizing the welding bond.

The Core

The rod's inner core---made of mild steel, cast iron, stainless steel, high-tensile steel, copper, bronze, brass or aluminum---should match the material to be welded.

Tensile Strength

The rod's core varies in tensile strength from 20,000 pounds per square inch (psi) or less to more than 100,000 psi. Properly applied welds can be stronger than the original metal.

Electrode Thickness

An electrode's thickness depends on the thickness of the joint you are creating and the metal used. A 3/32 rod or smaller is used on metal under ¼-inch thick. One-eighth inch rods and larger are used for metal more than ¼-inch thick.

The Coating

The flux coating controls and improves the welding process; it's made of blends of cellulose, iron powder or low hydrogen and blended with sodium, titania, potassium or iron oxide.

References

• Welding Electrodes
• Welding Machine and Rods

Resources

• Beginners' Guide to Welding