Copper Alloy ERCu
UNS C18980 · GB HSCu
ERCu is an essentially pure copper (~98%+ Cu) GMAW/GTAW filler, C18980 in the AWS A5.7 family, used to weld copper and copper alloys where the joint must carry heat or current.
Reference datasheet — ERCu 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 AW condition
ERCu tempers and conditions
ERCu is supplied in one standard condition, AW. AW is the default FabDigit quotes; the values on this page are for it.
Supply forms, finishes and certifications
Ways ERCu is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
ROD-ANN | Annealed straight-length TIG rod | Supply form |
WIRE-HD | Hard-drawn spool wire | Supply form |
OVERLAY | Copper overlay / cladding deposit on steel | Coating |
What is ERCu?
ERCu is an essentially pure copper (~98%+ Cu) GMAW/GTAW filler, C18980 in the AWS A5.7 family, used to weld copper and copper alloys where the joint must carry heat or current. The deposit provides 250 W/m·K thermal conductivity, about 40% IACS, 225 MPa tensile, 80 MPa yield and 35% elongation; forms include hard-drawn spool wire, annealed cut rod and overlay wire. Do not use it on oxygen-bearing (ETP) copper, and expect 200–500 °C preheat above roughly 3 mm section thickness, with service capped near 250 °C. Where joint conductivity is not required, ERCuSi-A runs cooler and easier. ERCu has a density of 8.9 g/cm³ (0.322 lb/in³), heavier than 77% of copper alloy grades. It melts at 1,065°C (1,949 °F). ERCu has a yield strength of 80 MPa (11.6 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 90% of copper alloy grades. Elongation at break is 35% and the elastic modulus is 115 GPa (16.7 Msi).
What is ERCu used for?
- copper busbar welding
- copper pipe/tube fabrication
- electrical conductor joints
- repair welding of copper vessels
Advantages
- Readily welded — 78/100, better than 91% of copper alloy grades
- Forms and bends easily — 92/100, better than 91% of copper alloy grades
- Conducts heat well — 250 W/m·K (144.4 BTU/hr·ft·°F), better than 81% of copper alloy grades
- Ductile — tolerates forming and impact — 35%, better than 80% of copper alloy grades
Limitations
- Low strength — 80 MPa (11.6 ksi), worse than 90% of copper alloy grades
ERCu properties
Typical room-temperature values for ERCu-AW; bars are the position among copper alloy grades.
Physical3
ERCu has a density of 8.9 g/cm³ (0.322 lb/in³), heavier than 77% of copper alloy grades. It melts at 1,065°C (1,949 °F).
Mechanical13
ERCu has a yield strength of 80 MPa (11.6 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 90% of copper alloy grades. Elongation at break is 35% and the elastic modulus is 115 GPa (16.7 Msi).
Thermal6
ERCu is rated for continuous service to 250°C (482 °F). It conducts heat at 250 W/m·K (144.4 BTU/hr·ft·°F), better than 81% of copper alloy grades. Thermal expansion is 17.7 µm/m·K (9.83 µin/in·°F).
Electrical3
ERCu conducts electricity at 40 % IACS, better than 74% of copper alloy grades.
Chemical & Environmental3
Corrosion resistance is good (62/100), worse than 57% of copper alloy grades.
Sustainability4
Producing a kilogram of ERCu takes about 57 MJ of energy and emits 3.8 kg of CO₂ — less than 52% of copper alloy grades. Typical recycled content is 35%.
Manufacturability8
ERCu's machinability is poor (30/100, worse than 67% of copper alloy grades); weldability very good (78/100); formability excellent (92/100).
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. ERCu is highlighted; hover a dot for its name, or open the interactive family chart.
Working with ERCu
Is ERCu easy to machine?
Deposit is soft and gummy — use sharp positive-rake tools, high speed, low feed and flood coolant; expect stringy chips.
Can ERCu be welded?
GMAW spray/pulse with Ar or Ar-He, or GTAW DCEN; preheat 200–500 °C for sections over ~3 mm and keep interpass hot due to the high thermal conductivity — do not use on oxygen-bearing (ETP) copper.
Can ERCu be formed, bent or molded?
Weld metal and annealed rod are highly ductile and can be peened, hammer-dressed or bent; hard-drawn spool wire is stiff and springy.
ERCu 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 |
|---|---|---|
| Sndeoxidizer/strengthener | ≤ 1 | 0.4 |
| Sideoxidizer | ≤ 0.5 | 0.25 |
| Mndeoxidizer | ≤ 0.5 | 0.25 |
| Pdeoxidizer | ≤ 0.15 | 0.05 |
| Al | ≤ 0.01 | |
| Pb | ≤ 0.02 | |
| Others (total) | ≤ 0.5 | |
| CuCu + Ag combined, AWS A5.7 minimum | ≥ 98 (balance) |
What surface finishes work on ERCu?
Cannot be anodized; wire-brush with clean stainless brushes, then leave bare, tin, nickel-plate or lacquer to control patina.
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).
Equivalent designations
Standards and trade names that resolve to Copper Alloy ERCu in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- C18980
- GB (China)
- HSCu
- Similar grades
- Cu 1897
How much does ERCu cost?
ERCu is a high-cost copper alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
ERCu — frequently asked
What is ERCu used for?
ERCu is typically used for copper busbar welding, copper pipe/tube fabrication, electrical conductor joints and repair welding of copper vessels. In short: highest-conductivity copper filler; matches pure copper joints; needs heavy preheat.
What is the yield strength of ERCu?
ERCu has a typical yield strength of 80 MPa (11.6 ksi) and a tensile strength of 225 MPa (32.6 ksi) — weaker than 90% of copper alloy grades.
Is ERCu easy to machine?
Not especially — machinability is rated poor (30/100, worse than 67% of copper alloy grades). Deposit is soft and gummy — use sharp positive-rake tools, high speed, low feed and flood coolant; expect stringy chips.
Can ERCu be welded?
Yes — weldability is rated very good (78/100). GMAW spray/pulse with Ar or Ar-He, or GTAW DCEN; preheat 200–500 °C for sections over ~3 mm and keep interpass hot due to the high thermal conductivity — do not use on oxygen-bearing (ETP) copper.
What surface finishes work on ERCu?
Cannot be anodized; wire-brush with clean stainless brushes, then leave bare, tin, nickel-plate or lacquer to control patina.
Can ERCu be formed, bent or molded?
Weld metal and annealed rod are highly ductile and can be peened, hammer-dressed or bent; hard-drawn spool wire is stiff and springy.
What is the maximum service temperature of ERCu?
ERCu is rated for continuous use to about 250°C (482 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does ERCu cost?
ERCu is a high-cost copper alloy ($$$$), 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
- AWS A5.7/A5.7M — Specification for Copper and Copper Alloy Bare Welding Rods and Electrodes — AWS (2011)
- UNS C18980 alloy data — Copper Development Association (copper.org) (2023)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
- ASM Handbook Vol.6 — Welding, Brazing and Soldering (copper welding) — ASM International (1993)
- ERCu / OK Autrod Cu welding wire datasheets — ESAB / Lincoln Electric (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.