What is Copper?
Copper is a chemical element with the symbol Cu (from Latin: Cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement.
What are the General Properties of Copper?
- Excellent heat conductivity
- Excellent electrical conductivity
- Good corrosion resistance
- Good biofouling resistance
- Good machinability
- Retention of mechanical and electrical properties at cryogenic temperatures
Where is Copper Used?
Uses of Copper:
- As a result of its excellent electrical conductivity, copper’s most common use is in electrical equipment such as wiring and motors.
- Since it corrodes slowly, copper is used in roofing, guttering, and as rain spouts on buildings.
- It is also used in plumbing and in cookware and cooking utensils.
- Commercially important alloys such as brass and bronze are made with copper and other metals.
- Gun metals and American coins are copper alloys.
- Copper sulfate is used as a fungicide and as an algicide in rivers, lakes, and ponds.
What are some of the alloys of Copper?
- CuCr1Zr – Alloy of Copper Chromium Zirconium
CuCr1Zr wire is used in connector pins.
- CuCr1 – Alloy of Chromium Copper
It was used for spot welding electrodes.
- BeCu – Beryllium Copper
It is used in oilfield tools, aerospace landing gears, beryllium copper sheets, etc.
- Gun Metal – Alloy of Copper Tin Zinc Lead
It is used in mirror cases, church doors, fonts, and statues.
- Brass – Alloy of Copper Zinc
It is used for applications where low friction is required such as locks, gears, bearings, doorknobs, ammunition casings and valves
- Bronze – Alloy of Copper Tin
It is used for applications such as springs, fasteners, masonry fixings, shafts, valve spindles, gears and bearings
What are the types of Copper and their Properties?
The copper most commonly used for sheet and strip applications complies with ASTM B370. It consists of 99.9 percent copper, and is available in six tempers designated by ASTM B370 as:
- 060 (soft)
- H00 (cold rolled)
- H01 (cold rolled, high yield)
- H02 (half-hard)
- H03 (three-quarter hard)
- H04 (hard)
- 060 (soft) Copper: Soft temper copper is extremely malleable and best suited for applications such as intricate ornamental work. It was historically used in building construction. Because of its low strength, heavy gauge material was required. As a result, the use of soft temper copper is not recommended for most building applications.
- H00 (cold rolled): With the development of cold-rolled copper many years ago, the gauge of the material could be reduced without compromising its low maintenance and long life. Cold rolled temper is less malleable than soft temper copper but is much stronger. It is by far the most popular copper temper currently used in construction.
The following table summarises the properties of cold-rolled copper:
Specific Gravity 8.89 – 8.94 Density 0.322lb./cu. in. at 68°F Thermal Conductivity 226 BTU/Sq Ft/Ft/Hr °F at 68°F Coefficient of Thermal Expansion 0.0000098/°F from 68°F to 572°F Modulus of Elasticity (Tension) 17,000,000 psi Tensile Strength 32,000 psi min. Yield Strength (0.5% Extension) 20,000 psi min. Elongation in 2″ – approx. 30% Shear Strength 25,000 psi Hardness –
Rockwell (F Scale)
Rockwell (T Scale)
54 min.15 min.
In general, cold rolled 1/8 hard temper (H00) copper is recommended for most roofing and flashing installations. Soft copper may be used where extreme forming is required such as in complicated thru-wall flashing conditions. However, it should be noted that cold-rolled copper offers far more resistance than does soft to the stresses induced by expansion and contraction. Copper roof sheet of higher temper should be specified only if indicated for specific and engineering applications requiring such higher tempers
- H01(Cold-Rolled, high yield 1/4 Hard): Flat test specimens, 1mm and 6mm thick, H01 temper.Applications: busbars, bus conductors, waveguides, hollow conductors, lead-in wires and anodes for vacuum tubes, vacuum seals, transistor components, glass-to-metal seals, coaxial cables, klystrons, microwave tubes, and rectifiers.Processing: Excellent hot and cold workability; good forgeability. Fabricated by bending, coining, coppersmithing, drawing and upsetting, hot forging and pressing, knurling, roll threading, shearing, spinning, swaging, and stamping.Corrosion Resistance: Good to excellent. Susceptible to galvanic corrosion when coupled with iron, aluminum, magnesium, lead, tin, and zinc. Good resistance to atmospheric, brackish water, seawater, and non-oxidizing acid corrosion, but avoid heating in oxidizing atmospheres or exposing to oxidizing acids, moist halogens, sulfides, ammonia, or solutions with ammonium ions.
- H02(Half Hard): Good to excellent corrosion resistance. Excellent hot and cold workability; good forgeability. Fabricated by coining, coppersmithing, drawing and upsetting, hot forging and pressing, spinning, swaging, stamping. Applications: high conductivity light-duty springs, electrical contacts, fittings, clamps, connectors, diaphragms, electronic components, resistance welding electrodes.Available as flat products, 1mm thick. 8.30 oz/ton Ag.
- H03(¾ Hard): Good to excellent corrosion resistance. Excellent cold workability. Fabricated by blanking, coining, forming and drawing, bending, heading, and upsetting.
Applications: electrical switches, springs, terminals, connectors, fuse clips, pen clips, weather stripping.Test specimen: flat products – 1mm thickness.
- H04 (hard): Good to excellent corrosion resistance. Excellent hot and cold workability; good forgeability. Fabricated by coining, coppersmithing, drawing and upsetting, hot forging and pressing, spinning, swaging, stamping. Applications: downspouts, gutters, roofing, gaskets, auto radiators, busbars, nails, printing rolls, rivets, and radio parts.Test specimen: flat products – 2mm thickness.
The following table summarises the type of copper and their significant properties:
|Temper Designation Standard||Min.Tensile Strength (Ksi)||Max.Tensile Strength (Ksi)||Yield Strength (Ksi) Min.|
|H00 Cold-Rolled 1/8 Hard||32||40||20|
|H01 Cold-Rolled, high yield 1/4 Hard||34||42||28|
|H02 Half Hard||37||46||30|
|H03 Three quarter Hard||41||50||32|