Copper Rounds

Copper Rounds

Copper rounds are circular, coin-like pieces made of pure copper, typically .999 fine (99.9% pure). They are primarily used for investment, collection, or decorative purposes. Unlike legal tender coins, they do not carry a face value but often feature intricate designs, including historical figures, animals, or custom engravings.

Key Features:

  • Purity: Usually .999 fine copper
  • Weight: Common sizes include 1 oz, 2 oz, and 5 oz
  • Uses: Investment, stacking, collecting, and artistic applications
  • Availability: Sold by mints, private manufacturers, and bullion dealers
  • Cost: Typically lower than silver or gold rounds, making them an affordable entry point for metal collectors

Precision Ground Copper Bars

Precision ground copper bars are high-quality, machined copper bars with tight dimensional tolerances. They are used in industrial, electrical, and manufacturing applications where high conductivity and precise sizing are essential.

Key Features:

  • Material: Often made from high-purity copper alloys such as C101 (oxygen-free), C110 (electrolytic tough pitch), or C145 (tellurium copper for machinability)
  • Tolerances: Precision-ground to specific dimensions, typically within a few thousandths of an inch
  • Applications: Used in electrical conductors, high-precision machining, aerospace, and electronic components
  • Advantages: High electrical and thermal conductivity, excellent corrosion resistance, and smooth surface finishes for optimal performance
Copper is classified into different grades based on its purity, composition, and intended application. For round copper products (such as rods, bars, and wires), the most common grades include:

Oxygen-Free Copper (OFC)

  • C10100 (OFHC - Oxygen-Free High Conductivity)
    • Purity: 99.99% Cu
    • Excellent electrical and thermal conductivity
    • Used in high-end electrical and electronic applications, such as transformers and semiconductors
  • C10200 (Oxygen-Free Copper)
    • Slightly lower purity than C10100
    • High ductility and corrosion resistance
    • Used in electrical conductors, anodes, and vacuum applications

Electrolytic Tough Pitch (ETP) Copper

  • C11000
    • Purity: ~99.90% Cu
    • High electrical conductivity (~101% IACS)
    • Contains oxygen, which can make it less weldable but great for electrical wiring, bus bars, and plumbing
  • C12200 (DHP - Deoxidized High Phosphorus Copper)
    • Contains ~0.015-0.040% phosphorus for improved corrosion resistance
    • Common in plumbing, heat exchangers, and refrigeration tubing

High Conductivity Copper Alloys

  • C14500 (Tellurium Copper)
    • Contains ~0.4-0.7% tellurium
    • Good machinability while retaining high conductivity
    • Used in electrical connectors and switch components
  • C14700 (Sulfur Copper)
    • Contains ~0.4-0.7% sulfur
    • Improved machinability over pure copper
    • Used in precision-machined electrical parts

Brass and Bronze (Copper Alloys)

  • C26000 (Cartridge Brass - 70/30 Cu-Zn)
    • High strength and good corrosion resistance
    • Used in ammunition, fasteners, and decorative applications
  • C36000 (Free Machining Brass - 60/40 Cu-Zn with lead)
    • Excellent machinability
    • Used in plumbing fittings, gears, and valves
  • C63000 (Nickel-Aluminum Bronze)
    • High strength, corrosion, and wear resistance
    • Used in marine applications, aerospace, and heavy machinery