GROUP A COPPER-BASE ALLOYS
RWMA Class 1 alloy TUFFALOY 88
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 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'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.
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
NICKEL-COPPER (55) and BERYLLIUM-NICKEL-COPPER (55A) 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-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 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 not 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.
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 dies. 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 dies. 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 die
facings, and for electrode facings used to upset studs and rivets. A material
for heavy-duty projection welding electrodes and dies.
RWMA Class 13 TUFFALOY 100W
TUNGSTEN
RWMA Class 14 TUFFALOY 100M
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,