RECOMMENDED USES OF RESISTANCE WELDING MATERIALS

GROUP A COPPER-BASE ALLOYS

RWMA CLASS 1 ALLOY • TUFFALOY 88

ZIRCONIUM-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

TUFFALOY 77 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 is used for welding

electrodes, projection welding electrodes, seam welding shafts and bearings, flash and butt welding electrodes, 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.

TUFFALOY Z 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 • TUFFALOY 55 AND 55A

BERYLLIUM-NICKEL-COPPER (55) are suited to welding steels having high electrical resistance, such as stainless steel.

NICKEL-COPPER (55A) is a beryllium-free alloy with properties similar to TUFFALOY 55.

Class 3 alloy is recommended for projection welding electrodes, and flash and butt welding electrodes. With its higher strength it is

also used on highly-stressed current-carrying parts such as electrode shanks and heavy-duty electrode holders. It is heat treatable.

RWMA CLASS 4 ALLOY • TUFFALOY 44

BERYLLIUM-COPPER has extremely high hardness, and is recommended for projection, flash and butt welding electrodes. 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 not excessive.

It is used frequently in the form of inserts, tooling facings, and seam welder bushings. It is available in the annealed condition which is

more readily machined and then subsequently heat treated.

GROUP B REFRACTORY METAL COMPOSITIONS

RWMA CLASS 10 • TUFFALOY 1W

TUNGSTEN 55% – COPPER 45%, suited for facings and inserts for projection welding electrodes and flash and butt welding electrodes.

It is recommended where (relatively) high electrical conductivity and some degree of malleability is desired.

RWMA CLASS 11 • TUFFALOY 10W

TUNGSTEN 75% – COPPER 25%, suited to similar applications as Class 10, and for facing on electrode forming electrodes. It is harder

than Class 10, and is for general use in projection welding electrodes.

RWMA CLASS 12 • TUFFALOY 20W

TUNGSTEN 80% – COPPER 20%, suited for electro-forming and electro-forging facings, and for electrode facings used to upset studs

and rivets. A material for heavy-duty projection welding electrodes.

RWMA CLASS 13 • TUFFALOY 100W (Pure Tungsten)

RWMA CLASS 14 • TUFFALOY 100M (Pure Molybdenum)

Class 13 & 14 materials are used primarily for welding or electro-brazing non-ferrous metals having relatively high electrical

conductivity. They are suited to cross-wire welding of copper and brass, and for welding copper wire braid to brass or bronze terminals.

Special set-ups and procedures are required.

TUFFALOY

welding data

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