1. Density of Pure Copper
The density of pure copper at room temperature (20°C) is a stable physical constant.
Density: 8.96 g/cm³
Equivalent to 8960 kg/m³
This relatively high density distinguishes copper from lighter metals such as aluminum and makes it suitable for applications requiring both weight and structural stability. The density changes slightly with temperature, but the value above is universally adopted in industrial production, material calculation, and trade.
2. Melting Point of Pure Copper
The melting point is the temperature at which copper transforms from a solid to a liquid under standard atmospheric pressure.
Melting point: 1083 °C (1356.15 K)
Pure copper has a high melting point, which means it remains stable under medium‑to‑high temperature conditions and does not easily soften or melt. This property supports its use in high‑temperature environments such as electrical components, heat exchangers, and casting.
3. Hardness of Pure Copper
Hardness reflects the resistance of a material to surface indentation or scratching. For pure copper, hardness varies slightly depending on its state (soft or hard):
Soft‑annealed pure copper:
Brinell hardness (HB): ~ 40–60 HB
Rockwell hardness (HRF): ~ 40–50 HRF
Cold‑worked / hard‑drawn pure copper:
Brinell hardness (HB): ~ 80–120 HB
Since pure copper is very soft in its annealed state, it is easy to bend, punch, and machine. Cold working (drawing, rolling, stamping) increases hardness but reduces ductility.
4. Tensile Strength and Elongation of Pure Copper
Tensile strength and elongation are key mechanical properties that determine formability and structural performance.
(1) Tensile Strength
Soft‑annealed pure copper:
Tensile strength: ~ 200–250 MPa
Cold‑worked / hard‑drawn pure copper:
Tensile strength: ~ 300–400 MPa
(2) Elongation (Ductility)
Elongation measures how much a material can stretch before breaking.
Soft‑annealed pure copper:
Elongation: ~ 40%–50%
This extremely high elongation means pure copper can be drawn into fine wires, rolled into thin sheets, or deeply drawn into complex shapes without cracking.
Cold‑worked pure copper:
Elongation drops to ~ 5%–20%
Higher strength comes at the cost of reduced ductility.
Summary
Pure copper is characterized by:
High density: 8.96 g/cm³
High melting point: 1083 °C
Low hardness in soft state: 40–60 HB
Moderate tensile strength: 200–250 MPa (annealed)
Excellent ductility: 40%–50% elongation
