The Physical, Mechanical and Chemical Properties of Copper

Copper is one of the most studied and widely used metals in engineering, construction, and MEP systems. Its properties make it indispensable for electrical wiring, plumbing, HVAC components, and architectural applications.

1. Physical Properties of Copper

Copper’s physical characteristics are what make it so valuable in electrical, thermal, and architectural applications.

Key Physical Properties

  • Distinctive reddish‑orange metallic luster
  • Excellent electrical conductivity (second only to silver among pure metals)
  • High thermal conductivity — ideal for heat exchangers and HVAC coils
  • Very ductile and malleable — easily drawn into wires or hammered into sheets
  • Moderate melting point:
    • 1084.62C (1357.77 K)
  • Boiling point:
    • 2561.85C (2835 K)
  • Density:
    • 8.96 g/cm³
  • Corrosion resistance — forms a protective oxide layer in air

2. Mechanical Properties of Copper

Copper’s mechanical behavior makes it ideal for piping, wiring, and mechanical components.

Key Mechanical Properties

  • High ductility — can be stretched into thin wires without breaking
  • High malleability — can be shaped or rolled easily
  • Good tensile strength (varies by alloy and temper)
    • Tensile properties are detailed in engineering guides for copper alloys
  • Excellent formability — suitable for extrusion, forging, and cold forming
  • Good fatigue resistance — important for HVAC vibration environments
  • Work‑hardening capability — copper strengthens when mechanically deformed

3. Chemical Properties of Copper

Copper’s chemical behavior is central to its corrosion resistance and antimicrobial performance.

Key Chemical Properties

  • Common oxidation states: +1 and +2
  • Reacts with oxygen to form:
    • Copper(I) oxide (Cu₂O)
    • Copper(II) oxide (CuO)
  • Does not react with water, but slowly reacts with atmospheric oxygen to form a protective layer
  • Forms green patina (copper carbonate) over time in moist air
  • High corrosion resistance due to stable oxide films
  • Acts as a catalyst in many chemical reactions
  • Intrinsic antimicrobial behavior — scientifically validated and documented in copper alloy research

Summary Table:

Property TypeKey CharacteristicsSources
PhysicalHigh electrical thermal conductivity, ductile, malleable, corrosion‑resistant, moderate melting pointCopper mineral
MechanicalStrong, formable, ductile, good tensile strength, work‑hardeningCopper Alloys
ChemicalOxidation states +1/+2, forms oxides, corrosion‑resistant, catalytic, antimicrobialCopper Catalysts

Here are The Scientific Evidence That Copper Has Intrinsic Antimicrobial Properties

Modern research overwhelmingly confirms that copper and its alloys naturally kill bacteria, viruses, and fungi without needing chemicals or coatings. This antimicrobial action is intrinsic—it comes from the metal itself.

Below are the key scientific findings supported by peer‑reviewed studies and authoritative reviews.

1. Copper Generates Reactive Oxygen Species (ROS)

Extensive research shows that copper ions trigger the formation of reactive oxygen species, which damage microbial cells.

  • Copper’s antimicrobial mechanism is “multifaceted,” with ROS generation being the main bactericidal mechanism, causing irreversible membrane damage.
  • ROS attack lipids, proteins, and DNA, leading to rapid cell death.

Why this matters: ROS generation is a built‑in chemical property of copper—this is one of the strongest proofs that its antimicrobial activity is intrinsic.

2. Copper Ions Disrupt Cell Membranes

Copper ions penetrate and destabilize microbial membranes.

  • Copper complexes “disrupt microbial membranes” and compromise membrane integrity.
  • This leads to leakage of essential nutrients and rapid cell collapse.

Why this matters: Membrane disruption is a universal antimicrobial mechanism effective against bacteria, fungi, and viruses.

3. Copper Causes DNA and RNA Damage

Copper ions bind to and degrade genetic material.

  • Copper complexes interact with DNA and proteins, causing DNA cleavage and enzyme inhibition.
  • Copper ions released from surfaces lead to RNA degradation in viruses.

Why this matters: This explains why copper kills even antibiotic‑resistant bacteria and enveloped viruses.

4. Copper Destroys a Wide Range of Microorganisms

Historical and modern studies show copper kills bacteria, fungi, and viruses at extremely low concentrations.

  • Copper inhibits numerous microbes including Bacillus, Candida, Aspergillus, and others, even at low concentrations.
  • Some organisms are completely inhibited at concentrations as low as 0.04 g/L.

Why this matters: This broad‑spectrum activity is rare and demonstrates copper’s intrinsic toxicity to microbes.

5. Copper Alloy Surfaces Kill Pathogens on Contact

Scientists have repeatedly demonstrated that copper alloy “touch surfaces” destroy harmful microorganisms.

  • Research confirms the intrinsic efficacy of copper alloy surfaces in killing a wide range of pathogens that threaten public health.

Why this matters: This is why copper is used in hospitals, transit systems, and high‑touch public environments.

6. The Oligodynamic Effect

Copper ions exhibit the “oligodynamic effect”—a toxic effect on microbes even at very low concentrations.

  • The oligodynamic effect was identified in 1893 and applies to copper ions, which kill bacteria, fungi, spores, and viruses at low doses.

Why this matters: This effect is a fundamental chemical property of copper, not a surface treatment.

Summary: What Science Have Proven

Across multiple independent studies:

  • Copper releases ions that damage membranes, DNA, and RNA.
  • Copper generates ROS that kill microbes.
  • Copper surfaces continuously kill bacteria and viruses.
  • Copper works at extremely low concentrations (oligodynamic effect).
  • Copper alloys retain antimicrobial activity indefinitely.

These findings confirm that copper’s antimicrobial behavior is intrinsic, natural, and scientifically validated.

1. Physical Properties of Copper

PropertyValue / Description
AppearanceReddish‑orange metallic luster
Density8.96 g/cm³
Melting Point1084.62C
Boiling Point25602562C
Thermal Conductivity401 W/(m·K)
Electrical ConductivityVery high (second only to silver)
Electrical Resistivity16.78 nΩ·m at 20°C
Thermal Expansion Coefficient16.64×106/K
Crystal StructureFace‑centered cubic (FCC)
Heat of Fusion13.26 kJ/mol
Heat of Vaporization300.4 kJ/mol
Molar Heat Capacity24.44 J/(mol·K)
Magnetic BehaviorDiamagnetic
ColorRed‑orange / reddish‑gold

2. Mechanical Properties of Copper

PropertyValue / Description
Tensile StrengthModerate (varies by alloy and temper)
Yield StrengthModerate (increases with work‑hardening)
DuctilityVery high — easily drawn into wires
MalleabilityVery high — easily shaped or rolled
HardnessSoft to moderately hard (depends on temper)
Elastic Modulus~110–128 GPa
Shear Modulus~48 GPa
Poisson’s Ratio~0.34
Fatigue ResistanceGood — suitable for vibration environments
Impact ResistanceModerate
Work‑HardeningStrong — copper becomes harder when deformed

3. Chemical Properties of Copper

PropertyValue / Description
Atomic Number29
Atomic SymbolCu
Common Oxidation States+1, +2
Reactivity with OxygenForms Cu₂O and CuO
Reaction with WaterDoes not react with pure water
Reaction in AirForms protective oxide layer; develops green patina over time
Corrosion ResistanceHigh — stable oxide films prevent degradation
Antimicrobial BehaviorIntrinsic; copper ions disrupt microbial membranes and DNA
Catalytic ActivityActs as a catalyst in many reactions
SolubilityInsoluble in water; soluble in acids like nitric acid
Electronegativity1.90 (Pauling scale)

Here are Five Alloys Widely Used in MEP construction, HVAC and Architectural Applications

Properties of Five Common Wrought Copper Alloys

Table: Physical, Mechanical & Chemical Properties of Common Wrought Copper Alloys

AlloyUNS NumberCompositionKey Physical PropertiesKey Mechanical PropertiesKey Chemical Properties
C11000 – Electrolytic Tough Pitch (ETP) CopperC11000~99.9% CuHigh electrical & thermal conductivity; density 8.96 g/cm³Tensile strength ~200–250 MPa; excellent ductility & formabilityOxidizes to Cu₂O/CuO; high corrosion resistance; antimicrobial
C12200 – Phosphorus‑Deoxidized Copper (DHP)C12200Cu + small PHigh thermal conductivity; good weldabilityTensile strength ~200–250 MPa; good ductility; excellent tube formabilityResistant to hydrogen embrittlement; stable oxide layer
C26000 – Cartridge BrassC2600070% Cu, 30% ZnGood thermal conductivity; golden colorTensile strength ~300–500 MPa; high ductility; good cold‑workingGood corrosion resistance; susceptible to dezincification in harsh environments
C28000 – Muntz MetalC2800060% Cu, 40% ZnGood conductivity; higher strength than C26000Tensile strength ~350–550 MPa; good hot‑workingBetter corrosion resistance than typical brasses; forms protective oxide
C70600 – 90/10 Copper‑NickelC7060090% Cu, 10% NiModerate conductivity; excellent seawater resistanceTensile strength ~275–380 MPa; good toughness; good weldabilityExceptional resistance to seawater corrosion, biofouling, and stress corrosion

Common Copper Alloys: Composition & Key Properties

Table: Composition & Properties of Major Copper Alloys

Alloy NameUNS NumberTypical CompositionKey Physical PropertiesKey Mechanical PropertiesKey Chemical Properties
ETP Copper (Electrolytic Tough Pitch)C11000~99.9% CuVery high electrical & thermal conductivity; density 8.96 g/cm³Tensile strength ~200–250 MPa; excellent ductility; soft to moderately hardForms Cu₂O/CuO; high corrosion resistance; antimicrobial; stable oxide layer
Oxygen‑Free Copper (OFHC)C1020099.95% Cu, very low O₂Highest electrical conductivity among copper alloys; excellent thermal conductivityTensile strength ~220–260 MPa; high ductility; excellent formabilityExtremely low oxygen prevents embrittlement; excellent corrosion resistance
Phosphorus‑Deoxidized Copper (DHP)C12200Cu + 0.015–0.040% PHigh thermal conductivity; good weldability; non‑sensitive to hydrogenTensile strength ~200–250 MPa; good ductility; ideal for tubingResistant to hydrogen embrittlement; stable oxide film
Cartridge BrassC2600070% Cu, 30% ZnGood thermal conductivity; golden color; moderate densityTensile strength ~300–500 MPa; excellent cold‑working; high ductilityGood corrosion resistance; may dezincify in harsh environments
Muntz MetalC2800060% Cu, 40% ZnGood conductivity; higher strength than C26000Tensile strength ~350–550 MPa; good hot‑workingForms protective oxide; better corrosion resistance than typical brasses
Aluminum BronzeC95400~85% Cu, 10–11% Al, 3–4% FeHigh strength; good thermal conductivity; bronze colorTensile strength ~500–700 MPa; excellent wear resistanceExceptional corrosion resistance, especially in seawater
Silicon BronzeC65500~97% Cu, 2.8–3.8% SiGood conductivity; high corrosion resistanceTensile strength ~350–550 MPa; good toughness; good formabilityExcellent resistance to atmospheric and chemical corrosion
90/10 Copper‑NickelC7060090% Cu, 10% NiModerate conductivity; excellent seawater resistanceTensile strength ~275–380 MPa; good weldability; good toughnessOutstanding resistance to seawater corrosion and biofouling
70/30 Copper‑NickelC7150070% Cu, 30% NiLower conductivity; very high corrosion resistanceTensile strength ~350–500 MPa; high strength; good fatigue resistanceSuperior resistance to erosion, stress corrosion, and seawater

Brief Summary of Copper and Its Alloys

Copper and its alloys stand out as some of the most reliable and durable engineering materials used in modern construction and MEP systems. Their exceptional mechanical strength, corrosion resistance, and long service life make them ideal for demanding environments ranging from residential plumbing to large‑scale commercial HVAC and electrical infrastructure. Copper’s excellent formability allows it to be drawn, rolled, extruded, or shaped into complex components without losing structural integrity, supporting efficient manufacturing and installation.

Beyond performance, copper is inherently sustainable. It is 100% recyclable without any loss of properties, enabling a fully circular material lifecycle that reduces environmental impact. Its intrinsic antimicrobial behavior—a natural ability to deactivate bacteria, viruses, and fungi—adds a unique health and safety advantage, especially in high‑touch or high‑traffic environments.

Copper alloys such as brasses, bronzes, and copper‑nickels expand this versatility even further. By adjusting alloying elements like zinc, tin, aluminum, or nickel, engineers can tailor strength, corrosion resistance, conductivity, and wear performance to meet specialized requirements. This combination of reliability, durability, sustainability, formability, and intrinsic functional benefits is why copper and its alloys remain foundational materials across the built environment.

One thought on “The Physical, Mechanical and Chemical Properties of Copper

Leave a Comment