Product Data Sheet  Copper Alloys

Chromium Copper  UNS-C18200

Chemical Composition

Copper(1) Chromium Iron Lead Silicon
Min / Max
Remainder
0.6 – 1.2
0.10
0.05
0.10
Nominal
99.1
0.9

(1) Copper value includes Silver

Note: Copper + Sum of Named Elements, 99.7% min)

Applicable Specifications

Product Specification
Bar
MILITARY MIL-C-19311
Forgings
MILITARY MIL-C-19311
Rod
MILITARY MIL-C-19311
Strip
MILITARY MIL-C-19311
Wire, Soft
ASTM F9

Common Fabrication Processes

Bending, Cold Working, Drawing, Extruding, Forging, Heading, Hot Working, Impacting, Rolling, Swaging.

Fabrication Properties

Joining Technique Suitability
Soldering
Good
Brazing
Good
Oxy-Acetylene Welding
Not Recommended
Gas Shielded Arc Welding
Good
Coated Metal Arc Welding
Not Recommended
Spot Weld
Not Recommended
Joining Technique Suitability
Seam Weld
Not Recommended
Butt Weld
Fair
Capacity for Being Cold Worked
Excellent
Capacity for Being Hot Formed
Good
Forgeability Rating
80
Machinability Rating
20

Mechanical Properties

Typical Room Temperature 20°C

Temper
Section Size
Cold Work
Tensile Strength
Yield Strength
(0.5% ext. under load)
Elongation
Rockwell Hardness
Vickers Hardness
(approx)
mm
%
MPa
MPa
%
B
C
F
30T
Tube
TL03
5.4
76
476
434
26
84
162
Flat Products
TF00
1
0
352
248
22
59
77
TB00
1
0
234
131
40
16
138
Rod
TF00
51
0
483
448
18
75
138
TF00
12.7
0
483
379
21
70
134
TH04
12.7
60
531
448
16
82
156
TB00
12.7
0
310
97
40
TD10
3.96
91
510
503
5
Tube
TD04
5.4
76
407
393
21
67
130
Rod
TF00
25.4
0
496
448
18
80
150
TF00
102
0
379
296
25
68
130
Flat Products
TD00
1
50
365
352
6
66
128
Tube
O61
2.4
0
276
103
50
59
65
Flat Products
TH01
1
50
462
407
14
79
148
Rod
TF00
76
0
448
379
18
70
134
TD04
12.7
60
393
386
11
65
126
TH01
3.96
90
593
531
14
Plate
TF00
76
0
386
276
30
68
132
TF00
51
0
400
290
25
70
134

* Vickers Hardness is approximate – converted from Rockwell Hardness using ASTM E140 tables

Physical Properties

Property
Metric Units
Imperial Units
Melting Point (Liquidus)
1075°C
1967°F
Melting Point (Solidus)
1070°C
1958°F
Density
8.89 gm/cm³ @ 20°C
0.321 lb/in³ @ 68°F
Specific Gravity
8.89
8.89
Coefficient of Thermal Expansion
17.6 x 10 -6 / °C (20-300°C)
9.8 x 10 -6 / °F (68-392°F)
Themal Conductivity *
323.6 W/m. °K @ 20°C
187.0 BTU/ft²/ft/hr/°F @ 68°F
Thermal Capacity (Specific Heat)
385.5 J/kg/°K @ 293°K
0.092 Btu/lb/°F @ 68°F
Electrical Resistivity *
2.16 microhm-cm @ 20°C
13.0 ohms-cmil/ft @ 68°F
Electrical Conductivity *
0.468 MegaSiemens/cm @ 20°C
80% IACS@ 68°F
Modulus of Elasticity (tension)
117,000 MPa
17,000ksi
Modulus of Rigidity
49,640 MPa
7,200ksi

.* Solution heat treated, cold worked (50% minimum) and aged.

Typical Uses

Consumer – Pencil-type & Light Soldering Guns: Tips, Rod Extensions

Electrical – Electrical Connectors, Electron Tube Grid Side Rods, Circuit Breaker Parts, Thermal Conductors Requiring Greater Strength than Copper, Cable, Electric Motor and Generator Components, Wire, High Temperature, Parts for Electronic Devices, Semi Conductor Bases, Contacts, Connectors, Switch Contacts, Electrical Conductors Requiring Greater Strength than Copper, Arcing and Bridging Parts, Switch Gears

Industrial – Plastic Mold Components, Structural Parts, Spot Welding Tips, Flash Welding Electrodes, Molds, Electrode Holder Jaws, Flash Welding Electrodes, Seam Welding Wheels, Current Carrying Shafts and Arms, Heat Sinks, Resistance Welding Machine Electrodes, Wear Plates on Heavy Equipment.

RWMA (Resistance Welder Manufacturers Association)

Electrode Material Standards

The mechanical and physical properties required of electrodes vary according to the application. The materials being used for electrodes fall into three groups:

• Group A — Copper Base Alloys.

• Group B — Refractory Metals and Refractory Metal Composites.

• Group C — Specialty Materials.

These groups are further subdivided as follows:

GROUP A. Copper Base Alloys

RWMA Class 1. Specifically recommended, because of its high electrical and thermal conductivity for spot welding aluminum alloys, magnesium alloys, some coated materials, brass and bronze.

RWMA Class 2. Class 2 material has slightly lower conductivity and higher mechanical properties than Class 1. Class 2 are general purpose resistance welding electrode materials for production spot and seam welding of most materials. They are suitable for spot welding electrodes, projection welding electrodes, seam welding electrodes, shafts and bearings, flash welding electrodes and current-carrying structural members, and are also available as high strength and high electrical conductivity castings for use as welding platens and secondary circuit structural members. Class 2 material should be used in the heat-treated condition.

These materials are stronger than Class I materials, but have slightly lower conductivity. They are used for the spot and seam welding of cold and hot-rolled steel, stainless steel and low conductivity brass and bronze. They are also used as flash welding dies and as electrodes for the welding of galvanized steel and other coated materials.

RWMA Class 3. Class 3 material has lower conductivity and higher mechanical properties than Class 2. It is recommended for projection welding electrodes, flash and upset welding electrodes, current-carrying shafts and bushings. As castings, Class 3 material is recommended for highly stressed welding structural current-carrying members and heavy-duty offset electrode shanks and holders. It is recommended for spot welding and seam welding steels having high electrical resistance, such as stainless steels, and it should be used in the heat-treated condition.

C18200 Extruded Rod

Available from Austral Wright Metals

Available from Austral Wright Metals

Specifications Hardness Electrical Conductivity Tensile Strength Minimum Yield Strength Elongation
% IACS MPa MPa %
RWMA Class 2 Group AASTM C18150ISO A2/2ASTM C18150ISO A2/2

75-83 HRB

134 – 156 HB

80 – 88
440 – 470
415
18 – 30

 

 

 

The technical advice and recommendations made in this Product Data Sheet should not be relied or acted upon without conducting your own further investigations, including corrosion exposure tests where needed. Please consult current editions of standards for design properties. Austral Wright Metals assumes no liability in connection with the information in this Product Data Sheet. Austral Wright Metals supplies a comprehensive range of stainless steels, copper alloys, nickel alloys and other high performance metals for challenging service conditions. Our engineers and metallurgists will be pleased to provide further data and applications advice.

 

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