Tungsten Copper Grades

RWMA CLASS RWMA NO. RWMA GENERAL USE RWMA DESCRIPTION
10 copper tungsten C74450 Flash and butt welding electrodes where good electrical and thermal conductivity is necessary and where a degree of malleability is desired. A powder metallurgical combination of 45% copper and 55% of the refractory metal tungsten. Not a true alloy. 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 C74400 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 combination of 25% copper and 75% of the refractory metal tungsten. Not a true alloy. 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 C74350 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 combination of 20% copper and 80% of the refractory metal tungsten. Not a true alloy. This combination produces dense, hard metals of superior wear resistance and strength at elevated temperatures. In addition, they possess good thermal and electrical conductivity.

Chemical Composition Group B Refractory Metals

RWMA CLASS CDA DESCRIPTION CU (incl. Ag) Fe W Cd Ni Co Cr Si Be Pb Zr Al
10 C74450 copper tungsten 43 - 47 -- rem. -- -- -- -- -- -- -- -- --
11 C74400 copper tungsten (ASTM B702 C1 D) 23 - 27 -- rem. -- -- -- -- -- -- -- -- --
12 C74350 copper tungsten (ASTM B702 C1 E) 18 - 22 -- rem. -- -- -- -- -- -- -- -- --

Minimum Physical Properties for Tungsten Copper Group B

GROUP B REFRACTORY METALS HARDNESS ROCKWELL(HRB) CONDUCTIVITY % I.A.C.S. ULTIMATE COMPRESSIVE StrENGTH ksi
CLASS 10 rod, bar,inserts 72 HRB 45% 135
CLASS 11 rod, bar,inserts 94 HRB 40% 160
CLASS 12 rod, bar,inserts 98 HRB 35% 170