Copper 110 (Electrolytic Tough Pitch) – Material Specification
Comprehensive technical specification for Copper 110 (ETP) including Canadian stock sizing, machinability data, common defects, and handling guidelines for fabrication and machining operations.
Material Overview & Common Uses
Copper 110, also known as Electrolytic Tough Pitch (ETP) copper (UNS C11000), is the most widely used copper alloy due to its high electrical conductivity (≥100% IACS annealed) and excellent thermal conductivity. It contains a minimum of 99.90% copper and 0.02–0.04% oxygen (as Cu2O) to control hydrogen embrittlement during welding and brazing. Common applications include electrical busbars, switchgear components, heat exchangers, plumbing fittings, roofing and flashing, RF shielding, and decorative architectural elements. In Canadian fabrication shops, it is frequently specified for custom electrical enclosures, busbar assemblies, and high-conductivity components for industrial machinery.
Core Technical Properties & Sizing
| Property | Value / Specification |
|---|---|
| Chemical Composition | Cu ≥99.90%, O 0.02–0.04% (balance Cu2O), trace impurities (Pb <0.005%, Fe <0.01%, S <0.005%) per ASTM B152/B152M and ASTM B187/B187M. |
| Physical Properties | Density 8.94 g/cm³ (0.323 lb/in³), Melting Point 1083°C (1981°F), Electrical Conductivity 101% IACS (annealed), Thermal Conductivity 391 W/m·K (226 BTU/ft·h·°F). |
| Mechanical Properties (Annealed) | Tensile Strength 200–250 MPa (29–36 ksi), Yield Strength 70–100 MPa (10–14 ksi), Elongation 45–55% in 2 in., Hardness 40–50 HRF. |
| Mechanical Properties (Half-Hard) | Tensile Strength 260–320 MPa (38–46 ksi), Yield Strength 200–260 MPa (29–38 ksi), Elongation 10–20%, Hardness 70–85 HRF. |
| Standard Canadian Sheet Sizes | 48" x 96" (1220 x 2440 mm) and 48" x 120" (1220 x 3050 mm) in gauges 16 ga (0.0625"), 14 ga (0.0781"), 12 ga (0.1094"), 10 ga (0.1406"), 1/8" (0.125"), 3/16" (0.1875"), 1/4" (0.250"). |
| Standard Bar Stock Sizes | Round bar diameters 1/4" to 6" (6.35–152.4 mm) in 12' (3.66 m) lengths; square and rectangular bar up to 4" x 6" (101.6 x 152.4 mm). |
| Tolerances (ASTM B152) | Thickness ±0.004" for 0.0625" sheet, ±0.006" for 0.125" sheet; width/length ±1/8" for sheared edges; flatness 1/4" in 48" for annealed temper. |
| Surface Finish | Mill finish (unpolished) with light oxide; optional bright or brushed finish available at premium. |
Machinability, Tooling & Feeds
Copper 110 has a machinability rating of 20% (free-cutting brass = 100%) due to its gummy, ductile nature. It produces long, stringy chips that can wrap around tooling and cause work-hardening if feeds are too light.
| Parameter | Recommendation |
|---|---|
| Machinability Rating | 20% (free-cutting brass = 100%) |
| Recommended Tooling | Sharp, polished carbide inserts (C2 grade) with positive rake geometry. High-speed steel (M2 or M42) tools with polished flutes for drilling and tapping. |
| Coolant | Copious water-soluble coolant (5–10% emulsion) to prevent built-up edge and maintain surface finish. |
| Turning (Carbide) – Speed | 600–900 SFM (183–274 m/min) |
| Turning (Carbide) – Feed | 0.005–0.015 in/rev (0.13–0.38 mm/rev) |
| Turning (Carbide) – Depth of Cut | 0.020–0.100 in (0.5–2.5 mm) |
| Drilling – Speed | 200–400 SFM (61–122 m/min) |
| Drilling – Feed (under 1/2") | 0.002–0.006 in/rev (0.05–0.15 mm/rev) |
| Tapping | Spiral-point taps with 2–3 flute design and high-lubricity tapping fluid. |
| Sawing (Carbide-tipped blades) | 4–6 teeth per inch for sheet/plate. |
| Sawing (Band saw) | 200–300 SFM (61–91 m/min) with variable pitch blades. |
| Welding (GTAW/TIG) | ERCu (deoxidized copper) filler rod. Preheat to 300–500°C (572–932°F) for sections over 1/8" to avoid hydrogen embrittlement. |
| Brazing | BCuP-5 or BAg-1a filler with flux. Avoid prolonged heating above 700°C (1292°F) to prevent oxygen diffusion. |
Common Defects & Quality Control
| Defect | Description / QC Check |
|---|---|
| Surface Oxidation / Discoloration | Brown or black patches from improper storage or exposure to moisture. |
| Edge Cracking | From shearing or slitting with dull blades, especially in half-hard temper. |
| Lamination / Separation | Internal voids from casting or rolling defects, visible as delamination during machining or bending. |
| Hydrogen Embrittlement | Intergranular cracking after welding or brazing if oxygen content is too high or preheat is insufficient. |
| Work-Hardening | Localized hardness from improper machining feeds causing tool chatter and poor surface finish. |
| Dimensional Variation | Out-of-tolerance thickness or width from mill rolling inconsistencies. |
Quality Control Checks: Verify thickness with micrometer at 3 points per sheet (edges and center). Check flatness on granite surface plate with feeler gauge. Perform Rockwell F hardness test on incoming stock. Conduct bend test (90° over radius equal to thickness) to check for edge cracking. Use spark test or conductivity meter (≥100% IACS) to confirm alloy identity. Reject material with visible laminations, edge cracks >1/16" deep, or hardness >85 HRF for annealed temper.
Storage, Handling & Racking Guidelines
- Store indoors in a dry, climate-controlled environment (RH <50%, temperature 15–25°C) to prevent oxidation and tarnishing.
- Do not store directly on concrete floors – use wooden pallets or rubber mats to avoid moisture wicking.
- Rack sheet vertically in A-frame racks with padded dividers (felt or rubber) to prevent scratching and edge damage.
- Bar stock should be stored horizontally on cantilever racks with protective sleeves or paper wrap.
- Avoid stacking heavy plates on top of thin sheets to prevent distortion.
- Use clean, dry gloves when handling to avoid oil and acid transfer from skin.
- For long-term storage (>6 months), apply a light coat of corrosion-inhibiting oil (e.g., LPS-3) or wrap in VCI (Vapor Corrosion Inhibitor) paper.
- Rotate stock FIFO (First In, First Out) to prevent age-related oxidation.
- Inspect incoming material for surface defects and measure thickness/width against PO tolerances.
- Segregate from steel and aluminum to prevent galvanic corrosion from contact.
- For cut pieces, deburr edges immediately and store in labeled bins with protective dividers.