4.4 Copper, Brass and Bronze Alloys

Forgings made from copper based alloys offer a number of advantages over products made by other processes. Dimensional precision is greater than by casting, working the alloys develops improved strength, and overall cost is modest. Zero draft forgings are possible, though not always practical. However, minimum draft forgings are being produced. Minimum draft capability is independent of alloy composition; alloys that can be forged by conventional means can be forged to minimum draft angles approaching 1°. Cored forgings are common and provide near-net shape parts with minimal waste.

Copper based alloys whose major alloying element is zinc are designated brasses. Those whose major alloying element is other than zinc are designated bronzes, such as silicon bronze and aluminum bronze. Those alloys with very high copper content, typically 98% or more, are generally designated "coppers", such as beryllium copper. Copper based alloys are designated by a six-character alpha-numeric system. The first character is C, indicating the copper base. The next five are numeric characters. The first numeric indicates the major group, and the remaining four designate the alloys within the group.

Copper based alloy forgings are corrosion resistant and pressure tight, and are commonly specified for high pressure liquid and gas handling applications such as fittings, plumbing hardware, refrigeration components and commercial valves. Strength is enhanced by the deformation that takes place in forging, making high strength brass forgings the choice in certain gears, bearings and hydraulic pumps. The homogeneous, porosity free structure of brass forgings makes them the ideal starting point for highly polished decorative door hardware and plumbing components.

Copper based alloys have been rated for forgeability, taking into account factors such as required forging pressure, die wear and hot plasticity. Forging brass, C37700, is the most forgeable and is rated at 100%. Brasses containing 35% to 40% zinc are rated at 90%, and coppers, with 99.9% minimum copper are rated at 65%. Silicon bronze, C65500, is the least forgeable at 40%.

Copper based alloys can be easily cleaned after forging and trimming by using a chemical processes or by other more environmentally friendly methods. Typical forging grades include:

CDA AMS
Composition
Common name
C37700 4614 59% Cu, 39% Zn, 2% Pb
Forging brass
C46400 4611-12 60% Cu, 39% Zn, 0.75% Sn
Naval brass
bars and rods
C63000 4640 81% Cu, 10% Al, 5% Ni, 3% Fe, 1% Mg
Nickel
aluminum bronze
64200 4633 91% Cu, 7.2% Al, 1.8% Si
Aluminum
silicon bronze
C67700 4619 65% Cu, 23% Zn, 4.5% Al, 4% Mn, 3% Fe, 0.5% Sn
Manganese
bronze

Additional information about the remaining alloys in this category can be obtained from the Copper Development Association, Inc. 405 Lexington Avenue, New York, NY 10017.

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Forgings made from copper based alloys offer a number of advantages over products made by other processes. Dimensional precision is greater than by casting, working the alloys develops improved strength, and overall cost is modest. Zero draft forgings are possible, though not always practical. However, minimum draft forgings are being produced. Minimum draft capability is independent of alloy composition; alloys that can be forged by conventional means can be forged to minimum draft angles approaching 1°. Cored forgings are common and provide near-net shape parts with minimal waste.

Copper based alloys whose major alloying element is zinc are designated brasses. Those whose major alloying element is other than zinc are designated bronzes, such as silicon bronze and aluminum bronze. Those alloys with very high copper content, typically 98% or more, are generally designated "coppers", such as beryllium copper. Copper based alloys are designated by a six-character alpha-numeric system. The first character is C, indicating the copper base. The next five are numeric characters. The first numeric indicates the major group, and the remaining four designate the alloys within the group.

Copper based alloy forgings are corrosion resistant and pressure tight, and are commonly specified for high pressure liquid and gas handling applications such as fittings, plumbing hardware, refrigeration components and commercial valves. Strength is enhanced by the deformation that takes place in forging, making high strength brass forgings the choice in certain gears, bearings and hydraulic pumps. The homogeneous, porosity free structure of brass forgings makes them the ideal starting point for highly polished decorative door hardware and plumbing components.

Copper based alloys have been rated for forgeability, taking into account factors such as required forging pressure, die wear and hot plasticity. Forging brass, C37700, is the most forgeable and is rated at 100%. Brasses containing 35% to 40% zinc are rated at 90%, and coppers, with 99.9% minimum copper are rated at 65%. Silicon bronze, C65500, is the least forgeable at 40%.

Copper based alloys can be easily cleaned after forging and trimming by using a chemical processes or by other more environmentally friendly methods. Typical forging grades include:

CDA AMS
Composition
Common name
C37700 4614 59% Cu, 39% Zn, 2% Pb
Forging brass
C46400 4611-12 60% Cu, 39% Zn, 0.75% Sn
Naval brass
bars and rods
C63000 4640 81% Cu, 10% Al, 5% Ni, 3% Fe, 1% Mg
Nickel
aluminum bronze
64200 4633 91% Cu, 7.2% Al, 1.8% Si
Aluminum
silicon bronze
C67700 4619 65% Cu, 23% Zn, 4.5% Al, 4% Mn, 3% Fe, 0.5% Sn
Manganese
bronze

Additional information about the remaining alloys in this category can be obtained from the Copper Development Association, Inc. 405 Lexington Avenue, New York, NY 10017.

Return to Table of Contents

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Forgings made from copper based alloys offer a number of advantages over products made by other processes. Dimensional precision is greater than by casting, working the alloys develops improved strength, and overall cost is modest. Zero draft forgings are possible, though not always practical. However, minimum draft forgings are being produced. Minimum draft capability is independent of alloy composition; alloys that can be forged by conventional means can be forged to minimum draft angles approaching 1°. Cored forgings are common and provide near-net shape parts with minimal waste.

Copper based alloys whose major alloying element is zinc are designated brasses. Those whose major alloying element is other than zinc are designated bronzes, such as silicon bronze and aluminum bronze. Those alloys with very high copper content, typically 98% or more, are generally designated "coppers", such as beryllium copper. Copper based alloys are designated by a six-character alpha-numeric system. The first character is C, indicating the copper base. The next five are numeric characters. The first numeric indicates the major group, and the remaining four designate the alloys within the group.

Copper based alloy forgings are corrosion resistant and pressure tight, and are commonly specified for high pressure liquid and gas handling applications such as fittings, plumbing hardware, refrigeration components and commercial valves. Strength is enhanced by the deformation that takes place in forging, making high strength brass forgings the choice in certain gears, bearings and hydraulic pumps. The homogeneous, porosity free structure of brass forgings makes them the ideal starting point for highly polished decorative door hardware and plumbing components.

Copper based alloys have been rated for forgeability, taking into account factors such as required forging pressure, die wear and hot plasticity. Forging brass, C37700, is the most forgeable and is rated at 100%. Brasses containing 35% to 40% zinc are rated at 90%, and coppers, with 99.9% minimum copper are rated at 65%. Silicon bronze, C65500, is the least forgeable at 40%.

Copper based alloys can be easily cleaned after forging and trimming by using a chemical processes or by other more environmentally friendly methods. Typical forging grades include:

CDA AMS
Composition
Common name
C37700 4614 59% Cu, 39% Zn, 2% Pb
Forging brass
C46400 4611-12 60% Cu, 39% Zn, 0.75% Sn
Naval brass
bars and rods
C63000 4640 81% Cu, 10% Al, 5% Ni, 3% Fe, 1% Mg
Nickel
aluminum bronze
64200 4633 91% Cu, 7.2% Al, 1.8% Si
Aluminum
silicon bronze
C67700 4619 65% Cu, 23% Zn, 4.5% Al, 4% Mn, 3% Fe, 0.5% Sn
Manganese
bronze

Additional information about the remaining alloys in this category can be obtained from the Copper Development Association, Inc. 405 Lexington Avenue, New York, NY 10017.

Return to Table of Contents

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