Copper Base Alloys

RWMA Class 1 alloy
CADMIUM-COPPER, suited to welding aluminum and magnesium alloys, coated materials, brass and bronze.

Class 1 alloy is superior to pure copper as an electrode material and is recommended as a general-purpose material for resistance welding use. It may be used for spot welding electrodes, seam welding wheels and welding fixture components. It is not heat treatable.

RWMA Class 2 alloy
CHROMIUM-COPPER, suited to welding cold- and hot-rolled steels, stainless steel, and low conductivity brasses and bronzes.

Class 2 alloy is a superior resistance welding electrode material, recommended for high-production operations. It's used for welding electrodes, projection welding dies, seam welding shafts and bearings, flash and butt welding dies, and current-carrying structural components. Available in forms for use as welding gun arms, welding platens and secondary-circuit structural members. It is heat treatable.

ZIRCONIUM-CHROMIUM-COPPER is suited to welding galvanized steel and other metallic-coated steel. This is a specially heat-treated alloy, which meets the minimum electrical conductivity and hardness specifications of Class 2 alloy.

RWMA Class 3 alloy
BERYLLIUM-COBALT-COPPER and BERYLLIUM-NICKEL-COPPER are suited to welding steels having high electrical resistance, such as stainless steel.

Class 3 alloy is recommended for projection welding dies, and flash and butt-welding dies. With its higher strength it is also used on highly current-carrying parts such as electrode shanks and heavy-duty electrode holders. It is heat treatable.

RWMA Class 4 alloy
BERYLLIUM-COPPER has extremely high hardness, and is recommended for projection, flash and butt-welding dies. It has lower conductivity than CLass 3 alloy but it is harder and more wear resistant. It should be considered where there is concern with high-pressure density and severe wear, but where heating, due to its low conductivity, is no excessive.

It is used frequently in the form of inserts, die facings, and seam welder bushings. It is available in the annealed condition, which is more readily machined, and then subsequently heat-treated.

RWMA Class 5 alloy
ALUMINUM-COPPER is recommended as a high-strength backing for other resistance material, in flash welding dies, secondary-circuit welder arms, knees, platens, etc. It can be used to advantage in structural, current-carrying members in welding fixtures where high strength, wear resistance, and non-magnetic properties are required.