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Copper Chromium Zirconium C18150, RWMA Class 2, AWS J1.3


Copper Chromium Zirconium has the addition of Zirconium to chromium copper to improve creep resistance at high operating temperatures and reduces sticking of electrodes to the work during spot welding of galvanized/coated materials. C18150 is specified mainly for electrode applications. Chromium Zirconium is an RWMA Class 2 material and is stronger than the RWMA Class 1 materials. 


C18150 has a chemical composition of 98.5% copper, 1% chromium, and 0.1% zirconium.


Available in Rod, Bar, Plate, Wire/Coil.


Typical usages of RWMA Class 2 Copper Alloy: C18150 is recommended for spot and seam, welding cold and hot rolled steels, coated materials, current-carrying shafts and arms, back-up bars for both resistance and arc welding, and electrical current carrying structural parts.


It is used extensively for cap-style resistance welding electrodes. It can provide less sticking and resistance for much longer than its counterpart copper -chromium in some specific situations.



Back-up Electrodes Bushings Caps & Shanks Casting Wheels
Centrifugal Casting Molds Circuit Breaker Parts Collector Connector Collector Housing
Connector Bar Connectors Connection Lead Bar Continuous Casting Molds
Cross Wire Welding Electrodes & Components Damper Ring/Finger Dies & Fixtures Electrode Holders and Adaptors
Electrical & Mechanical Power Components Flash & Butt Welding Dies Flexible Connector Heat Flux Components
Injection Blow Molds & Dies Lead Conductor Bar Motor End Rings Neutral Bus Bar
Non-Sparking Applications Nut & Stud Welding Electrodes Power Generation Products Power Semiconductor Bases
Resistance Welding Electrodes Rotor Coil Bars Seam Weld Wheels Series Loop Segment
Shafts Slip Rings Slot Wedge Snap Rings
Special Nipple Terminal Box Connectors Threaded Electrodes Transmission Devices
Water Clip Welding Arms Welding Connectors Welding Platens
Wire for Additive Manufacturing      


Item Name: Copper Chromium Zirconium Alloy C18150
RWMA (Resistance Welding Manufacturing Alliance) Class: Class 2
Principal Element: Cu, Cr, Zr
Minimum Hardness Rockwell (up to 1" dia.): HRB 75
Minimum Electrical Conductivity (% IACS): 75
Metal Stock Availability: Stocked in mill form or precision cut to your specifications.



Length for Round, Hexagon, Square, Octagon, Rectangle, Special Shapes: All sizes in standard lengths up to 12 ft
Special Sizes
Diameter for Round, Hexagon, Square, Octagon, Rectangle, Special Shapes: 1/8 to 15 1/8 in
Special Sizes
Thickness for Plate: 1/8 to 10 in
Special Sizes
ISO Certification: 9001:2015 (Registration # 10002745 QM15 Valid until 2024-08-21)
Reports: Certification of Compliance
Chemical Analysis
Final Inspection
Material Test Reports
Mechanical and Physical Testing: Elongation
Grain Size
Nondestructive Testing: Chemical Analysis
Liquid Penetrant
Alloy Applications Cross Reference Chart C15000 C18150 C18000 C18200 C17510 C17200 C15760
Axial Conductors X            
Back-up Electrodes X X X X X X X
Bushings X X X X X    
Caps & Shank X X X X X X X
Casting Wheels X X   X      
Casting Wheels and Dam Blocks     X   X X  
Centrifugal Casting Mold X X X X      
Circuit Breaker Parts X X   X     X
Collector Connector X X   X       
Collector Housing X X   X      
Connector Bar X X   X      
Connectors X X X X X   X
Connection Lead Bar X X   X      
Continuous Casting Molds X X X X X X  
Cross Wire Welding Electrodes & Components X X X X X X X
Damper Ring/Finger X X X X      
Dies & Fixtures X X X X X X  
Die Casting Pistons     X   X X  
Die Casting Plunger Tips     X   X X  
Electrode Holders & Adaptors X X X X X X  
Electrical & Mechanical Power Components X X X X X X X
Flash & Butt Welding Dies X X X X X X X
Flexible Connector X X   X      
Heat Flux Components X X X X X   X
Injection Blow Molds & Dies   X X X X X  
Joining Components X   X   X X X
Lead Conductor Bar X X   X      
Motor End Rings X X X X X    
Neutral Bus Bar X X   X      
Non-Sparking Applications   X X X X X  
Nut & Stud Welding Electrodes X X X X X X  
Performance Engine Components     X   X X  
Permanent Molds     X   X X X
Power Generation Products X X X X      
Power Semiconductor Bases X X   X      
Resistance Welding Electrodes X X X X X X  
Rotor Coil Bar X X   X      
Seam Weld Wheels X X X X X X  
Series Loop Segment X X   X      
Shafts X X X X X X  
Slip Rings X X   X      
Slot Wedge X X X X      
Snap Rings X X   X      
Special Nipple X X   X      
Terminal Box Connectors X X   X      
Threaded Electrodes X X X X X X  
Transmission Devices X X   X     X
Water Clip X X   X      
Wear Plates           X  
Welding Arms X X X X X X  
Welding Blocks X   X   X X  
Welding Connectors X X X X X X  
Welding Platens X X X X X X  

NOTE: C18150 Copper Chromium Zirconium and C15000 Copper Zirconium are both good replacements for C16200 Copper Cadmium. C18150 Copper Chromium Zirconium is a good replacement because of its precipitation hardened copper alloy that provides high strength at elevated temperatures with good conductivity. C15000 strength properties are developed through cold working  (similar to C16200) whereas C18150 strength properties are developed primarily from heat treating (precipitation hardening), which is an advantage for large parts.