General Use and Description of RWMA Group B and C

 

RWMA CLASS RWMA GENERAL USE * RWMA DESCRIPTION
10 COPPER TUNGSTEN Flash and butt welding electrodes where good electrical and thermal conductivity is necessary and where a degree of malleability is desired. A powder metallurgical blend of 45% copper and 55% of the refractory metal tungsten. This combination produces dense, hard metals of superior wear resistance and strength at elevated temperatures. In addition, they possess good thermal and electrical conductivity.
11 COPPER TUNGSTEN Projection welding electrodes, flash and butt welding electrodes, light upsetting, and seam welding bushings. Harder than Class 10 and used where moderate pressure is required. This material can also be used for spot welding low conductivity steels such as stainless. A powder metallurgical blend of 25% copper and 75% of the refractory metal tungsten. This combination produces dense, hard metals of superior wear resistance and strength at elevated temperatures. In addition, they possess good thermal and electrical conductivity.
12 COPPER TUNGSTEN Heavy duty projection welding electrodes, electro-forming and electo-forging electrodes facings for upsetting of studs and rivets, cross wire welding of large diameter wire and rod. A powder metallurgical blend of 20% copper and 80% of the refractory metal tungsten. This combination produces dense, hard metals of superior wear resistance and strength at elevated temperatures. In addition, they possess good thermal and electrical conductivity.
13 TUNGSTEN Cross wire welding of copper and brass, resistance brazing and some upsetting. Welding of braided copper wire to other materials. Tungsten is extremely hard and has low ductility. It cannot be machined with cutting tools but can be ground to required contours. It does not alloy with nonferrous materials. Tungsten has the highest melting point (3,422 °C, 6,192 °F) of all the metals.
14 MOLYBDENUM Cross wire welding of copper and brass, resistance brazing and some upsetting. Welding of braided copper wire to other materials. Not as hard as Class 13 and can be drilled and machined to special contours. With relatively good thermal conductivity, molybdenum has a melting point of 2,623 °C (4,753 °F) and has one of the lowest coefficients of thermal expansion among commercially used metals.
RWMA CLASS RWMA GENERAL USE * RWMA DESCRIPTION
20 DISPERSION STRENGTHENED COPPER Welding of metallic coated metal such as galvanized steel, terne plate, etc. A dispersion of aluminum oxide within a copper matrix that exhibits good resistance to softening, and room temperature properties consistent with RWMA Class 2.

 

* General suggested applications, not to be interpreted as the optimum for any specific application.
   RWMA Table 1.8.2