Overview
Copper is one of the oldest engineering metals, valued for its exceptional electrical and thermal conductivity, natural corrosion resistance, ductility, and antimicrobial properties. It is reddish-orange in color, easily formed and joined, and widely used in electrical wiring, plumbing, heat exchangers, and roofing.
Mechanical Properties
| Property | Value |
|---|---|
| Density | 8,960 kg/m³ (0.324 lb/in³) |
| Young's Modulus | 117 GPa (17 × 10⁶ psi) |
| Yield Strength (annealed) | 70 MPa (10,000 psi) |
| Ultimate Tensile (annealed) | 220 MPa (32,000 psi) |
| Ultimate Tensile (hard drawn) | 380 MPa (55,000 psi) |
| Elongation at break | 45-50% (annealed) |
| Hardness | 40-50 BHN (annealed) |
| Melting Point | 1085°C |
Thermal & Electrical Properties
| Property | Value |
|---|---|
| Thermal Conductivity (20°C) | 401 W/m·K |
| Specific Heat | 385 J/kg·K |
| Coefficient of Thermal Expansion | 16.5 × 10⁻⁶ /°C |
| Electrical Resistivity | 1.72 × 10⁻⁸ Ω·m |
| Electrical Conductivity | 58 MS/m (100% IACS) |
Common Alloys
| Alloy | UNS | Key Properties | Applications |
|---|---|---|---|
| C11000 (ETP) | C11000 | 101% IACS, pure copper | Electrical wire, bus bars |
| C12200 (DHP) | C12200 | Deoxidized, weldable | Plumbing tube, refrigeration |
| Brass (Cu-Zn) | C2xxx | Higher strength, machinable | Valves, fittings, hardware |
| Bronze (Cu-Sn) | C5xxx | Higher strength, corrosion resistant | Bearings, gears, marine |
| Cu-Ni 90/10 | C70600 | Seawater corrosion resistance | Marine piping, condensers |
Applications
- Electrical: Building wiring, motor windings, transformers, bus bars, printed circuits
- Plumbing: Water supply tubing (Type L/M/K), refrigerant lines, gas distribution
- Heat transfer: Heat exchanger tubes, radiators, air conditioning coils, solar collectors
- Roofing & architecture: Long-lasting green patina, flashing, gutters, decorative elements
- Marine: Cu-Ni piping for seawater service, propellers, hull antifouling coatings
- Industrial: Chemical process equipment (non-sparking, corrosion resistant)
Corrosion Resistance
Copper naturally forms a protective green patina (basic copper carbonate/sulfate) in outdoor environments, which stops further corrosion. It resists:
- Fresh water and most non-oxidizing acids
- Atmospheric exposure (centuries-long service life for roofing)
- Neutral/alkaline soils
Copper is attacked by:
- Oxidizing acids (nitric acid, concentrated sulfuric)
- Ammonia and ammonium compounds (stress corrosion cracking)
- Sulfides and high-sulfur environments
- Highly acidic water (pH < 6)
Summary
Copper (density 8960 kg/m³) is the standard for electrical conductivity and a preferred material for plumbing and heat transfer. Its high thermal conductivity (401 W/m·K), ductility, corrosion resistance, and antimicrobial properties make it irreplaceable in many applications. It costs significantly more than carbon steel but its performance justifies the premium in electrical and heat-transfer service.
Related Engineering Tools
- Metal Weight Calculator Hub — Complete metal weight calculation hub
- Steel Weight Calculator — Steel plate, beam and section weight
- Aluminum Weight Calculator — Aluminum sheet and bar weight
- Copper Weight Calculator — Copper busbar and sheet weight
- Density Calculator — General density calculations
Copper Density vs Temperature
| Temperature (°C) | Density (kg/m³) | Notes |
|---|---|---|
| 20 | 8,960 | Standard reference |
| 100 | 8,890 | Slight decrease |
| 200 | 8,800 | |
| 300 | 8,700 | |
| 400 | 8,600 | Annealing range |
| 500 | 8,490 | |
| 600 | 8,380 | Hot working |
| 800 | 8,150 | |
| 1085 | 7,990 | Melting point (liquid) |
Copper Alloys Density Comparison
| Alloy | Density (kg/m³) | Composition | Use |
|---|---|---|---|
| Pure Copper (C110) | 8,960 | 99.9% Cu | Electrical conductors, busbars |
| Brass (C360) | 8,500 | Cu + 35% Zn | Machining, decorative |
| Bronze | 8,800 | Cu + 10% Sn | Bearings, marine |
| Cupronickel 70/30 | 8,940 | Cu + 30% Ni | Seawater piping |
| Beryllium Copper | 8,250 | Cu + 2% Be | Non-sparking tools, springs |
| Phosphor Bronze | 8,800 | Cu + 5% Sn + 0.2% P | Electrical contacts, springs |
Copper Weight Calculation
Example: 1000 x 100 x 10mm copper busbar:
- W = 0.001 m3 x 8960 kg/m3 = 8.96 kg
- Compare: same aluminum = 2.7 kg (copper 3.3x heavier)
- Compare: same steel = 7.85 kg (copper 14% heavier)
Copper vs Aluminum for Electrical Conductors
| Property | Copper | Aluminum | Advantage |
|---|---|---|---|
| Density | 8,960 kg/m3 | 2,700 kg/m3 | Al 70% lighter |
| Conductivity (% IACS) | 100% | 61% | Cu 64% better |
| Conductivity (MS/m) | 59.6 | 37.7 | Cu better |
| Tensile Strength | 220 MPa | 70 MPa | Cu 3x stronger |
| Cost per kg | Higher | Lower | Al cheaper |
| Weight for same conductance | Heavier | Lighter | Al lighter for same Amps |
For the same current-carrying capacity, an aluminum conductor needs about 1.6x the cross-section area but weighs only 47% as much as copper. This is why overhead transmission lines use aluminum (with steel core for strength), while building wiring uses copper.
Frequently Asked Questions
What is the density of copper in kg/m3? Pure copper density is 8,960 kg/m3 (8.96 g/cm3). This is one of the highest densities among common engineering metals — 14% heavier than steel and 3.3x heavier than aluminum.
How much does a copper busbar weigh per meter? A 40x5mm copper busbar weighs 1.79 kg/m. A 50x10mm busbar weighs 4.48 kg/m. Use our Copper Weight Calculator for precise results with any dimensions.
Is copper heavier than steel? Yes, copper (8,960 kg/m3) is about 14% heavier than carbon steel (7,850 kg/m3). However, copper's superior electrical conductivity (100% IACS) makes it irreplaceable for electrical applications despite the weight penalty.
What is the melting point of copper? Copper melts at 1,085°C. This is lower than iron/steel (~1,500°C) but higher than aluminum (660°C). The liquid density at melting point is approximately 7,990 kg/m3.