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APPENDIX C: THE BASICS OF RESISTANCE WELDING
UB25 LINEAR DC RESISTANCE WELDING CONTROL
C-2
990-665
Electrode Selection
Correct electrode selection strongly influences how weld heat is generated in the weld area. In general,
use conductive electrodes such as a RWMA-2 (Copper alloy) when welding electrically resistive parts
such as nickel or steel so that the weld heat is generated by the electrical resistance of the parts and the
contact resistance between the parts. Use resistive electrodes such as RWMA-13 (Tungsten) and RWMA-
14 (Molybdenum) to weld conductive parts such as copper and gold because conductive parts do not
generate much internal heat so the electrodes must provide external heat. Use the following Electrode
Selection Table for selecting the proper electrode materials.
MATERIAL
ELECT
RWMA
TYPE
MATERIAL
ELECT
RWMA
TYPE
Alumel
-2
Alumel
-2
Alumel
-2
Chromel
-2
Alumel
-2
Dumet
-2
Aluminum
-1
Aluminum
-1
Aluminum
-1
Aluminum
Alloys
-1
Aluminum
-1
Cadmium
Plating
-1
Aluminum
-1
Tinned Brass
-14
Aluminum
-1
Tinned
Copper
-14
Aluminum
-1
Gold Plated
Dumet
-2
Aluminum
-1
Gold Plated
Kovar
-2
Aluminum
-1
Kovar
-2
Aluminum
-1
Magnesium
-1
Aluminum
-1
Cold Rolled
Steel
-2
Aluminum
-1
Stainless Steel
-2
Beryllium
Copper
-2
Beryllium
Copper
-2
Beryllium
Copper
-2
Brass
-2, -14
Beryllium
Copper
-2
Copper
-14
Beryllium
Copper
-2
Tinned
Copper
-14
Beryllium
Copper
-2
Nickel
-2
MATERIAL
ELECT
RWMA
TYPE
MATERIAL
ELECT
RWMA
TYPE
Beryllium
Copper
-2
Cold Rolled
Steel
-2
Beryllium
Copper
-2
Stainless Steel
-2
Brass
-2, -14
Brass
-2, -14
Brass
-2, -14
Tinned Brass
-14
Brass
-2, -14
Consil
-2
Brass
-2, -14
Constantan
-2
Brass
-2, -14
Copper
-14
Brass
-2, -14
Tinned
Copper
-14
Brass
-2, -14
Dumet
-2
Brass
-2, -14
Nichrome
-2
Brass
-2, -14
Nickel
-2
Brass
-2, -14
NiSpan C
-2
Brass
-2, -14
Paliney 7
-2
Brass
-2, -14
Silver
-11, -14
Brass
-2, -14
Cold Rolled Steel
-2
Brass
-2, -14
Stainless Steel
-2
Bronze
-2, -11
Bronze
-2, -11
Bronze
-2, -11
Tinned Copper
-14
Bronze
-2, -11
Iron
-2
Bronze
-2, -11
Nichrome
-2
Bronze
-2, -11
Nickel
-2
Chromel
-2
Chromel
-2
Chromel
-2
Constantan
-2
Chromel
-2
Copel
-2
Chromel
-2
Copper
-14