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| |
R.W.M.A. RECOMMENDED ELECTRODE MATERIALS FOR SPOT
WELDING
Using Conventional Spot Welding Methods
LEGEND
Block Interpretation
|
WELDABILITY
|
ELECTRODES AGAINST 
|
|
 ELECTRODES
AGAINST
|
SPECIAL INFORMATION
|
WELDABILITY
A- Excellent
B- Good
ELECTRODES, R.W.M.A. Specifications
I- Group A, Class 1-Tuffaloy 88
II- Group A, Class 2 -Tuffaloy 77 & Tuffaloy Z
III- Group A, Class 3 -Tuffaloy 55
Materials indicated in squares are second choice, example
SPECIAL INFORMATION
1- Special conditions required
2 - Good practice recommends cleaning before welding
3 - If plating is heavy, we strength is questionable.
Data based on Resistance Welding Equipment Standards, Bulletin 16, a
publication of the Resistance Welder Manufacturers Association.
TO WELD SIMILAR METALS
|
FERROUS
|
Tin Plate Steel
|
Terne Plate Steel
|
Galvanized Iron Zinc Plate
|
Cadmium Plate Steel
|
Chrome Plate Steel
|
Stainless Steel 18-8 Type
|
Scaly H.R. Steel
|
C.R. Steel H.R. Steel (clean)
|
|
READ BLOCK UNDER METAL TO BE WELDED
|
B |
I |
A |
I |
A |
I
|
B |
I |
A |
II |
A |
III
|
B |
I
II |
A |
II |
| I |
3 |
I |
3 |
I
|
3 |
I |
3 |
II |
3 |
III
|
|
I
II |
2 |
II |
|
| NON-FERROUS |
Aluminum
|
Aluminum Alloys Duraluminum
|
Cupro Nickel
|
Nickel Silver
|
Nickel
|
Nickel Alloy Monel Nichome (High Res)
|
Brass Yellow 25-40% Zinc
|
Phosphor Bronze Grade A, C & D
|
Silicon Bronze Everdur Olympic Duronze Herculoy
|
|
|
B |
I
|
B |
I
|
A |
II |
B |
II |
A |
II |
A |
II |
B |
II |
AB |
II |
AB |
II |
| I
|
2 |
I
|
2 |
II |
|
II |
|
II |
|
II |
|
II |
|
II |
|
II |
|
TO WELD DISSIMILAR METALS
|
FERROUS ALLOYS
|
Stainless Steel 18-8 Type
|
Chrome Plate Steel
|
Cadmium Plate Steel
|
Galvanized Iron Zinc Plate
|
Terne Plate Steel
|
Tin Plate Steel
|
|
Cold Rolled Steel Hot Rolled Steel, Clean
|
A |
II
|
A |
II |
B |
II |
B |
I |
A |
I
|
B |
I |
| III |
|
II |
3 |
II |
3 |
II |
3 |
II |
3 |
II |
3 |
|
Tin Plate Steel
|
B |
II
|
B |
II |
B |
I
|
B |
I |
B |
I
|
|
| I |
|
I |
3 |
I |
3 |
I |
3 |
I |
3 |
|
Terne Plate Steel
|
B |
II |
B |
II |
B |
I
|
B |
I |
|
| I |
3 |
I |
3 |
I |
3 |
I |
3 |
|
Galvanized Iron Zinc Plate
|
B |
II |
B |
II |
B |
I |
|
| I |
3 |
I |
3 |
I |
3 |
|
Cadmium Plate Steel
|
B |
II |
B |
II |
|
| I |
3 |
I |
3 |
|
Chrome Plate Steel
|
A |
III
|
|
| II |
3 |
|
NON-FERROUS
ALLOYS
|
Nickel Alloys
|
Nickel
|
Phosphor Broze
|
Silicon Bronze
|
Yellow Brass
|
Nickel Silver
|
|
Cupro Nickel
|
B |
II |
B |
II |
B |
II |
B |
II |
B |
II |
B |
II |
| II |
|
II |
|
II |
|
II |
|
II |
|
II |
|
|
Silicon Bronze Everdur – Olympic Bronze – Herculoy
|
B |
II |
B |
II |
B |
II |
A |
II |
B |
II |
|
| II |
|
II |
|
II |
|
II |
|
II |
|
|
Nickel Silver
|
B |
II |
B |
II |
B |
II |
B |
II |
|
| II |
1 |
II |
|
II |
1 |
II |
|
|
Nickel Alloys
|
A |
II |
B |
II |
|
|
ALUMINUM
|
|
ALUMINUM ALLOYS DURALUMINUM
|
B |
I
|
| I
|
2 |
|
| II |
|
II |
|
|
Stainless Steel 8-8 Type
|
B |
II |
B |
II |
| III
|
1 |
II
|
3 |
MINIMUM PHYSICAL PROPERTIES FOR R.W.M.A. ALLOYS
Published Standards of the Resistance Welder Manufacturers
Association
|
GROUP A Copper Base Alloys
|
|
CLASS
|
TUFFALOY NUMBER
|
PROPORTIONAL LIMIT TENSION P.S.I.
|
HARDNESS ROCKWELL
|
CONDUCTIVITY PER CENT I.A.C.S.
|
ULTIMATE TENSILE STRENGTH P.S.I.
|
ELONGATION % IN 2" OR 4"DIAMETER
|
|
ROUND RODS
Up to 1" diameter
|
1
2
3 |
88
77
55 |
17,500
35,000
50,000 |
65-B
75-B
90-B |
80
75
45 |
60,000
65,000
100,000 |
13
13
9 |
|
1" to 2" diameter
|
1
2
3 |
88
77
55 |
15,000
30,000
50,000 |
55-B
65-B
90-B |
80
75
45 |
50,000
55,000
95,000 |
14
13
9 |
|
2" to 3" diameter
|
1
2
3 |
88
77
55 |
15,000
25,000
50,000 |
55-B
70-B
90-B |
80
75
45 |
50,000
55,000
95,000 |
15
13
9 |
|
BARS Square Rectangular Hexagon Up to 1" thick
|
1
2
3 |
88
77
55 |
20,000
35,000
50,000 |
55-B
70-B
90-B |
80
75
45 |
60,000
65,000
100,000 |
13
13
9 |
|
Over 1" thick
|
1
2
3 |
88
77
55 |
15,000
25,000
50,000 |
50-B
65-B
90-B |
80
75
45 |
50,000
55,000
100,000 |
14
13
9 |
|
FORGINGS Up to 1"
|
1
2
3 |
88
77
55 |
20,000
22,000
50,000 |
55-B
65-B
90-B |
80
75
45 |
45,000
55,000
94,000 |
12
13
9 |
|
1" to 2"
|
1
2
3 |
88
77
55 |
15,000
21,000
50,000 |
50-B
65-B
90-B |
80
75
45 |
40,000
55,000
94,000 |
13
13
9 |
|
Over 2"
|
1
2
3 |
88
77
55 |
15,000
20,000
50,000 |
50-B
65-B
90-B |
80
75
45 |
40,000
55,000
94,000 |
–
12
5 |
|
All sizes
|
4 |
44 |
85,000 |
33-C |
20 |
140,000 |
.5 |
|
CASTINGS All sizes
|
2
3
4
5 |
77
55
44
66 |
20,000
45,000
60,000
12 to 16,000 |
55-B
90-B
33-C
65 to 85-B |
70
45
18
10 to 15 |
45,000
85,000
90,000
65 to 75,000 |
12
5
.5
2 to 10 |
|
GROUP B Refractory Metal Compositions
|
Rods, Bars & Inserts |
10
11
12
13
14 |
1W
10W
20W
100W
100M |
|
72-B
94-B
98-B
69-A
85-B |
35
28
27
30
30 |
135,000
160,000
170,000
200,000
200,000
|
Ultimate
Compression Strength P.S.I. |
|
A
World Of Resistance Welding