C18150 Chromium Zirconium Copper

C18150 Chromium Zirconium Copper

Cr 0.50 - 1.50%
CHROMIUM
470 - 630 MPa
TENSILE STR
RWMA Class 2
SPEC STD
C18150 chromium zirconium copper, also known as CuCr1Zr, is a precipitation-hardened high-conductivity copper alloy containing 0.50–1.50% chromium and 0.03–0.30% zirconium supplied as rod and bar (RWMA Class 2). It pairs 78–85% IACS conductivity with good strength and softening resistance, making it ideal for resistance-welding electrodes, motor commutators, and power connectors.
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Product Overview

C18150 chromium zirconium copper, commonly designated CuCr1Zr (EN CW106C), is a copper alloy with 0.50–1.50% chromium and 0.03–0.30% zirconium, plus iron and silicon each below 0.1% and copper as the balance (copper plus additions 99.70% minimum). It is manufactured to UNS C18150 (RWMA Class 2, EN CW106C) for rod and bar requiring high conductivity with strength after precipitation hardening.

Strengthened by solution treatment followed by aging, C18150 reaches tensile strength of 470–630 MPa with yield strength of 420–500 MPa and electrical conductivity of 78–85% IACS in the age-hardened and drawn condition. Its zirconium addition raises the recrystallization and softening temperature, so it keeps hardness and conductivity under welding heat, and reduces electrode sticking when spot welding galvanized steel. Density is 8.9 g/cm³ and elastic modulus about 117 GPa.

C18150 is the standard choice for resistance-welding electrodes, welding wheels, and tips, and is also used for motor commutators, current-carrying shafts, and power connectors. Linsy Copper supplies C18150 chromium zirconium copper rod and bar to RWMA Class 2, with low-MOQ custom production (typical lead time 10–60 days), in-house CNC machining and surface finishing, an MTR/MTC for every order, and optional SGS testing on request. Contact our Shenzhen team for a quotation within one hour.

Key Features

High conductivity (78–85% IACS) combined with medium strength
Precipitation-hardened Cr + Zr for strength and high softening temperature
RWMA Class 2 material for resistance-welding electrodes and tips
Excellent stress-relaxation and high-temperature softening resistance
Zirconium reduces electrode sticking on galvanized and coated steels
Conforms to UNS C18150 / EN CuCr1Zr (CW106C) for electrodes and connectors

Available Sizes

Copper Shape Thickness (mm) Width/Diameter (mm) Length (m)
Bar - Φ5-200 1-6
Wire - Φ0.05-10 Customize
Sheet 0.25-6 500-2500 1-6
Plate 6-200 200-3000 1-6
Strip 0.15-6 8-610 Customize
Tube OD: φ2-600; WT:φ0.2-100mm - 1-6
Coil 0.15-6 3-1250 1-6
Foil < 0.15 10-1350 Customize
Profile Customized Customize Customize

* Custom sizes available upon request. Contact our sales team for special requirements.

Technical Specifications

Precision data for engineering decisions. All values tested per ASTM standards.

01 Chemical Composition

Element Min % Max % Notes
Cr 0.50 1.50 Primary hardener
Zr 0.03 0.30 Softening resistance
Fe 0 0.08 Impurity
Si 0 0.10 Impurity
Others 0 0.20 Total impurities
Cu – Remainder Balance

02 Mechanical & Physical Properties (Age-Hardened)

Property Typical Range Condition Unit
Tensile Strength (UTS) 470 - 630 Age-hardened MPa
Yield Strength (0.2% offset) 420 - 500 Age-hardened MPa
Elongation at Break 4 - 16 Age-hardened %
Electrical Conductivity 78 - 85 Age-hardened % IACS
Hardness (Vickers) 140 - 190 Age-hardened HV
Elastic Modulus 117 All tempers GPa

Applications & Use Cases

Proven solutions across diverse industries. From aerospace to marine environments.

Frequently Asked Questions

Find answers to common questions about C18150 chromium zirconium copper specifications, welding use, and ordering.

C18150 (CuCr1Zr) is the standard RWMA Class 2 material for resistance-welding electrodes, seam-welding wheels, and tips, because it stays hard and conductive under welding heat. It is also used for motor commutators, current-carrying shafts, and power connectors where high conductivity meets moderate strength.
In the age-hardened and drawn condition C18150 carries 78–85% IACS — roughly 80% of pure copper's conductivity — while delivering 470–630 MPa tensile strength. That strength-with-conductivity balance is why it replaces copper and bronzes in welding and current-carrying parts.
The zirconium addition raises the alloy's recrystallization and softening temperature and changes the surface behavior during spot welding of galvanized or coated steel, so the electrode tip sticks far less and weld quality stays consistent over long runs.
Common tempers are R470, R540, and R600 (increasing strength with falling elongation): R470 gives 470+ MPa UTS and 8% elongation, R540 reaches 540–630 MPa at 4% elongation. Selection balances strength against formability for the electrode or part geometry.
It machines only moderately (machinability about 20% of free-cutting brass C36000) and is best finish-machined after aging. It brazes and laser-welds well; resistance welding of the part itself is not recommended. Linsy provides in-house CNC machining to the required electrode profile.
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