Copper Alloy C18100
UNS C18100
C18100 is a chromium-zirconium copper from the wrought lightly alloyed copper family, precipitation hardened to 490 MPa yield, 550 MPa tensile and 165 HB (85 HRB) while retaining 80 % IACS and 320 W/m·K.
Reference datasheet — C18100 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the TH04 condition
C18100 tempers and conditions
C18100 is supplied in 7 conditions, soft to hard. TH04 is the default FabDigit quotes; the values on this page are for it.
Compare all 7 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Fully softened material for severe forming or as a machining stock before re-solution treating. | 95 | 250 | 42 | 58 HB | 88 % IACS |
Solution heat treated | Soft supersaturated condition for deep forming or machining before ageing; conductivity is temporarily low. | 105 | 260 | 40 | 60 HB | 42 % IACS |
Solution heat treated and cold worked, full hard | Cold-drawn stock supplied for customers who will age-harden after machining. | 340 | 400 | 14 | 120 HB | 45 % IACS |
Solution heat treated and precipitation hardened | Standard aged condition for large sections, forgings and electrode blanks where cold work is impractical. | 390 | 470 | 18 | 145 HB | 82 % IACS |
TD01 and precipitation hardened | Intermediate strength with retained ductility for parts needing some subsequent bending. | 420 | 495 | 16 | 152 HB | 81 % IACS |
TD02 and precipitation hardened | Half-hard aged strip/rod balancing strength and formability. | 455 | 520 | 14 | 158 HB | 80 % IACS |
TH04Default TD04 and precipitation hardened | The usual stocked bar/rod condition: peak strength and hardness with ~80% IACS conductivity. | 490 | 550 | 13 | 165 HB | 80 % IACS |
What is C18100?
C18100 is a chromium-zirconium copper from the wrought lightly alloyed copper family, precipitation hardened to 490 MPa yield, 550 MPa tensile and 165 HB (85 HRB) while retaining 80 % IACS and 320 W/m·K. The chromium and zirconium additions resist softening up to a 450 °C service limit, which is why the alloy is drawn and forged into resistance welding electrodes, rotor bars, contact wire and electrode holders. It cuts gummy, the heat-affected zone of a fusion weld over-ages, and properties depend on controlled solution treatment and aging; C18200 chromium copper is the simpler option where 450 °C softening resistance is not needed. C18100 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,070°C (1,958 °F). C18100 has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 88% of copper alloy grades. Elongation at break is 13% and the elastic modulus is 130 GPa (18.9 Msi).
What is C18100 used for?
- resistance welding electrodes
- rotor bars
- contact wire
- electrode holders
Advantages
- High service temperature — 450°C (842 °F), better than 98% of copper alloy grades
- Stiff — 130 GPa (18.9 Msi), better than 89% of copper alloy grades
- High strength — 490 MPa (71.1 ksi), better than 88% of copper alloy grades
- Conducts heat well — 320 W/m·K (184.9 BTU/hr·ft·°F), better than 84% of copper alloy grades
- High electrical conductivity — 80 % IACS, better than 84% of copper alloy grades
Limitations
- Needs corrosion protection — 48/100, worse than 96% of copper alloy grades
C18100 properties
Typical room-temperature values for C18100-TH04; bars are the position among copper alloy grades.
Physical3
C18100 has a density of 8.89 g/cm³ (0.321 lb/in³), heavier than 72% of copper alloy grades. It melts at 1,070°C (1,958 °F).
Mechanical14
C18100 has a yield strength of 490 MPa (71.1 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 88% of copper alloy grades. Elongation at break is 13% and the elastic modulus is 130 GPa (18.9 Msi).
Thermal6
C18100 is rated for continuous service to 450°C (842 °F). It conducts heat at 320 W/m·K (184.9 BTU/hr·ft·°F), better than 84% of copper alloy grades. Thermal expansion is 17 µm/m·K (9.44 µin/in·°F).
Electrical3
C18100 conducts electricity at 80 % IACS, better than 84% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is fair (48/100), worse than 96% of copper alloy grades.
Sustainability4
Producing a kilogram of C18100 takes about 57 MJ of energy and emits 3.8 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 25%.
Manufacturability8
C18100's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability fair (45/100); formability fair (40/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the copper alloy family
Yield strength against density for every copper alloy grade FabDigit runs. C18100 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with C18100
Is C18100 easy to machine?
Machines like tough copper — gummy, needs sharp positive-rake carbide, high speed, generous coolant and chip breaking; aged (TH04/TF00) stock cuts far better than solution-treated.
Can C18100 be welded?
GTAW/EBW/laser possible with matching filler but the heat-affected zone over-ages and loses ~30–40 % strength; re-solution treat and re-age where possible, or use brazing at the lowest practical temperature.
Can C18100 be formed, bent or molded?
Form in TB00/O61 and age afterwards; aged tempers tolerate only gentle bends (min bend radius ≈ 2–3 t) because of low residual ductility.
C18100 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Crprincipal precipitation hardener | 0.4 – 1.5 | 0.8 |
| Zrraises softening resistance | 0.08 – 0.2 | 0.13 |
| Mgdeoxidiser / strengthener | 0.04 – 0.08 | 0.06 |
| CuCu + named elements ≥ 99.5 % | balance |
What surface finishes work on C18100?
Not anodizable; electroplate Ni/Ag or Ni-flash + Au for contacts, or protect the natural copper surface with benzotriazole/lacquer; polishes to a bright copper finish.
Surface treatments FabDigit runs on copper alloy parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
How much does C18100 cost?
C18100 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
C18100 — frequently asked
What is C18100 used for?
C18100 is typically used for resistance welding electrodes, rotor bars, contact wire and electrode holders. In short: 80 % IACS at 490 MPa; 450 °C softening resistance; beryllium-free electrode copper.
What is the yield strength of C18100?
C18100 has a typical yield strength of 490 MPa (71.1 ksi) and a tensile strength of 550 MPa (79.8 ksi) — stronger than 88% of copper alloy grades. Strength varies by condition: see the 7 listed tempers.
Is C18100 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 67% of copper alloy grades). Machines like tough copper — gummy, needs sharp positive-rake carbide, high speed, generous coolant and chip breaking; aged (TH04/TF00) stock cuts far better than solution-treated.
Can C18100 be welded?
With care — weldability is rated fair (45/100). GTAW/EBW/laser possible with matching filler but the heat-affected zone over-ages and loses ~30–40 % strength; re-solution treat and re-age where possible, or use brazing at the lowest practical temperature.
What surface finishes work on C18100?
Not anodizable; electroplate Ni/Ag or Ni-flash + Au for contacts, or protect the natural copper surface with benzotriazole/lacquer; polishes to a bright copper finish.
Can C18100 be formed, bent or molded?
Form in TB00/O61 and age afterwards; aged tempers tolerate only gentle bends (min bend radius ≈ 2–3 t) because of low residual ductility.
What is the maximum service temperature of C18100?
C18100 is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between C18100-TH04 and C18100-O61?
TH04 is the default condition — the usual stocked bar/rod condition: peak strength and hardness with ~80% IACS conductivity. O61: fully softened material for severe forming or as a machining stock before re-solution treating. Yield strength is 490 MPa in TH04 versus 95 MPa in O61.
How much does C18100 cost?
C18100 is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM B441 — Copper-Chromium-Zirconium (C18100) Rod, Bar and Shapes — ASTM International (2019)
- CDA/UNS Alloy Datasheet C18100 — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- RWMA Bulletin 16 — Resistance Welding Electrode Materials, Class 3 — AWS/RWMA (2017)
- CuCrZr (C18150/C18100) high-conductivity alloy datasheet — Wieland / Ningbo Powerway (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.