Please fill out the following form to submit a Request for Quote to any of the following companies listed on
Introduction
The content of this article contains everything you need to know about copper and brass forging.
You will learn:
What is Copper and Brass Forging?
Types of Copper and Brass Forging
Products Made from Brass Forging
Copper and Brass Used for Forging
And much more …
Chapter 1: What is Copper and Brass Forging?
Copper and brass forging is the deformation of copper and brass for the purpose of manufacturing complex and intricate shapes. The temperature at which copper and brass are forged is precision controlled and monitored due to their melting temperatures, which are between 1675°F and 1981°F (913°C and 1082°C). The use of copper and brass for forging is because of their malleability and ductility, factors that make them ideal for forging.
The wide use of copper and brass for forging is due to their exceptional properties. They can be forged into several shapes, which can include complex and intricate ones. The products from forging copper and brass are of the highest quality with excellent dimensional tolerances and bright smooth finishes that compare favorably with other metal worked products.
Chapter 2: Types of Copper and Brass Forging
Most of the typical forging methods are used to work copper and brass. The choice of methods is dependent on the type of copper and brass since each alloy has different characteristics and properties that influence how they can be forged. The forging of copper and brass has existed for thousands of years with both having been discovered prior to the beginning of the modern calendar.
Regardless of the type of forging, every method includes the use of a die or forging tool that has been designed in accordance with the requirements of the product to be produced. In all cases, as is common to forging, the billet, ingot, or sheet of copper or brass is subject to force that changes the grain structure of the metal to achieve the desired configuration.
Cold Forging
Cold forging involves changing the structure of copper or brass below their recrystallization temperature, which is normally close to room temperature, by squeezing the metal into a die. The die can be a closed or open die and includes an upper and lower die half.
Die
The process for cold forging begins with the formation of the die, which is engineered to have the shape and form of the part to be forged. In order to be able to withstand the forging process, the die is made of pre-hardened steel that is heat treated to achieve the necessary hardness. The type of hardening process varies depending on the complexing of the die since dies with deep cavities and complex designs need to be tougher to avoid cracking and breakage of the die.
Dies for copper and brass are made of H21, H11, and H13 hot die steel with a Rockwell hardness of 48 to 52. Strength and durability are necessary for die manufacturing since they are used to produce multiple parts at high volume. Although copper and brass are ductile and malleable, they still require force in order to produce components and parts of the correct shape and complexity.
Forging
Copper and bronze alloys selected for cold forging are chosen in accordance with their composition and properties. The process of cold forging improves their hardness and ductility. Additionally, the dimensional accuracy, toughness, and surface finish of the metals is enhanced. Cold forging of copper and brass involves applying force to the metals at normal room temperature, which includes impacting, stretching, bending, and shaping without the application of heat for the metals to be deformed.
With cold forging, an ingot, billet, or sheet of copper or brass is placed in the lower half of the die that is attached to the anvil of a vertical press. The upper half of the die is attached to the ram. The force for the process is supplied by a motor that brings the ram down on the billet or ingot. As the force of the ram presses down on the metal, the metal takes the shape of the die. The complete process takes place rapidly producing new shapes in an instance.
Both cold and hot forging can be closed or open with closed die forging being a process where the halves of the die move together and completely enclose the workpiece. Open die forging, known as smithing, compresses the workpiece into a die that has simple shapes such as angles and various flat shapes. What differentiates open die forging from closed die forging is that the metal is never completely enclosed in open die forging.
Copper and brass are ideal for cold forging due to their ductility and malleability. Unlike the forging of steel, iron, and stainless steel, copper and brass require less force to achieve the desired shape and make it possible to forge high volumes of parts in a wide range of shapes and sizes.
Hot Forging
With hot forging, the billet, ingot, or sheet of copper or brass is heated to a specific temperature such that when compressed by the force of the ram it will fill both halves of the die. The hot forging of copper and brass produces parts with exceptional density and without flaws and with repeatable dimensional accuracy. Similar to cold forging, the surface of hot forged copper or brass has a clean lustrous finish.
Heating
The heating process involves slugs that have been extruded from ingots into rods of the proper length for filling the die cavity. The cut slugs are heated to the forging temperature, which is between 1350°F up to 1700°F (732°C up to 927°C). The heating process is carefully controlled to ensure that the slug is properly prepared for forging. If it is too cold or not hot enough, the final product will be poorly formed and flawed.
Forging
Whether the forging process is cold or hot, it follows the same parameters of using force to reshape the workpiece. With hot forging, the die is heated prior to placing the slug in the lower half of the die. This procedure is used to ensure proper metal flow. As with cold forging, the downward stroke of the ram forces the slug to deform to the shape and dimensions of the die.
The malleability and ductility of copper and brass normally require one stroke of the ram to force the metal to the shape of the die, which is unlike steel or iron that may necessitate several strokes in order to achieve the desired shape. The use of a single stroke to reach conformity to complex and intricate shapes removes the need for a line of progressive dies. Additionally, a higher volume of parts can be produced, which varies between 100 to 1200 per hour with the common rate being 200 to 600 per hour.
During the application of force by the ram, the grain structure of copper and brass are changed to ensure uniform density with exceptional physical and mechanical properties. It is the nature of the properties of copper and brass, and its lighter weight, that makes the parts produced using copper and brass the first choice for various processes.
Trimming
The weight of the copper or brass slug is slightly higher than that which would be required to completely fill the die cavity. The die halves have a gutter that allows the access metal from the die cavity to escape as flash that needs to be trimmed and removed during finishing. Dies are precision engineered such that the amount of flash is limited to avoid any damage to the forged piece.
The thickness of the flash varies in accordance with the pressure from the ram, the quantity of excess metal, the temperature of the slug, and the temperature of the die. Although trimming is the common practice for removing flash, parts with tight outside dimensions require closer trimming using a process known as shaving.
Rolled Ring Forging
Rolled ring forging is a special form of forging that is used in combination with cold forging. The process involves the creation of perfectly shaped rings using rollers, a mandrel, and force. It is the ideal method for making smooth and symmetrical copper and brass rings.
Cold Forging
Initially, the copper or brass stock is cut by size and weight and upset, which reduces the height of the stock and increases its diameter such that it reaches the desired diameter of the ring to be produced. This process is completed using open cold forging. To achieve the necessary donut shape, the round workpiece is pierced through the middle.
The proper preparation of the workpiece is necessary to achieve the desired dimensions of the final rolled ring. The characteristics of the copper or brass is a prime consideration much like it is for any other forging process since the donut shape has to be sufficiently malleable.
Forging
The mechanism for the rolled ring forging process includes a combination of parts that work together to shape the donut shape to the appropriate height and thickness. The power for the process is provided by the drive roller, which turns the donut as it is shaped. The pierced hole is placed over an idler roller that works with the drive roller to diminish the thickness of the donut as it is turned. Two axial rollers that are located opposite the drive roller and control the height of the donut as it turns. Each of the various parts are designed to manipulate the workpiece in order to achieve the desired dimensions for the ring.
Prior to being placed into the rolled ring mechanism, the donut is heated to a point just below its recrystallization point to increase its ductility and malleability. As the donut rotates at the force of the drive roller, the drive roller and idler decrease the thickness of the donut while increasing its diameter. The diameter and height of the rolled ring is programmed into the rolled ring forming mechanism such that the deformation does not exceed the design parameters.
Due to the properties and characteristics of copper and brass, the rolled ring forging process is completed in very slow and progressive steps such that the deformation is completed with precision and accuracy.
Warm Forging
Warm forging is a process that is commonly used for working with alloyed steel as an alternative to cold forging. For certain shapes, manufacturers use the warm forging process since it provides them with other methods for forging copper and brass. The process for warm forging involves raising the temperature of the metal slightly above room temperature or the temperature for cold forging but not as high as the temperature used for hot forging.
The use of warm forging increases tool life, provides for a wide range of part tolerances, and can help improve surface finishes. The precision control of the temperature makes it possible to achieve very close tolerances and avoids any shrinkage, which is common for hot forged parts. The close adherence to tolerances and precision lowers the need for finishing processes such as the removal of flash. The yield strength of copper and brass decreases while their ductility increases, which makes it possible to have more deformation.
The warm forging process is referred to as precision forging since it improves the quality of forged parts. It does not require the forming force of cold forging and can produce intricate and complex shapes. The critical factor for warm forging is strict and meticulous control of the deformation temperature and the type of heating equipment.
Chapter 3: The Types of Brass Used for Forging
When anyone thinks of brass, their very first conclusion is that brass is an alloy of copper and zinc, which many people believe are the only metals used to produce brass. In reality, there are many types of brass, each of which is a different combination of a group of metals that are combined with copper and zinc. Each form of brass can be forged using hot forging to form plumbing fittings, knobs, handles, and other forms.
During its long and rich history from ancient Mesopotamia up until today, brass has been altered, changed, and adapted to serve a wide range of functions with various types of brass specifically created to fit the needs of unique applications. Brass was one of the first metals to be forged using an anvil and hammers.
Alpha Brass (CuZn)
Alpha brass is a single-phase alloy that contains 55% to 65% copper and 35% to 45% zinc. It is very ductile and can be cold worked. Alpha brass is known for its good corrosion resistance and is used in drawing applications. Cold working of alpha brass hardens it. The addition of iron, aluminum, or silicon to alpha brass improves its mechanical properties. The main characteristic that makes alpha brass so popular is its extremely pleasing appearance, which makes it ideal for architectural and decorative purposes.
Alpha Beta Brass (CuZn40)
Alpha beta or duplex brass has 37% to 45% zinc with an alpha and beta grain structure, which gives alpha beta brass a balanced composition. It is a very hard brass with low ductility and exceptional strength. The high zinc content of alpha beta brass makes it less expensive than alpha brass but makes it susceptible to corrosion.
Alpha beta brass is alloyed with different elements to adjust its properties to fit the needs of various applications. The addition of tin enhances alpha beta brass’ resistance to corrosion while the addition of iron further enhances its corrosion resistance and makes alpha beta brass tougher. As with the addition of these alloys, the addition of various other elements, including arsenic and lead, are used to adjust and change the mechanical and physical properties of alpha beta brass.
Although alpha beta brass is difficult to work at room temperature, it can be easily worked at higher temperatures and can be extruded into bars or can be hot forged using closed dies to produce intricate and complex shapes. The one caveat to the process is precision control of the cooling rate in order to achieve a single-phase alpha structure.
Beta Brass (CuZn15)
Beta brass has an extremely high zinc content reaching as high as 50% with a 50% copper content. Of the three classifications of brass, beta brass is the hardest and strongest, which makes it ideal for strength applications such as fasteners. Although the hardness and strength make beta brass ideal for certain applications, they also limit its workability and ductility.
The strength of beta brass has made it the first choice of brass for applications that require durability and resistance to wear. For such uses, beta brass is cast and hot worked. The high zinc content of beta brass makes it the brightest and least gold colored of the three brasses.
Leaded Brass (CuZn39Pb3)
The creation of leaded brass was to improve the machinability of brass by adding a small percentage of lead, usually 1% to 3%. Aside from their machinability, leaded brasses have exceptional corrosion resistance. The lead content increases its machinability by acting as a chip breaker and tool lubricant, which makes leaded brass an ideal metal for use with Swiss screw machines.
The general term leaded brass covers an array of leaded brasses that have low, medium, and high lead content with lead content of up to 3.5% being possible. In the grain structure of leaded brass, lead is seen on the grain boundaries of the microstructure. The appearance of lead in leaded brass changes as the amount of zinc increases.
Naval Brass (CuZn40Sn1)
Naval brass is a combination of 60% copper, 39% zinc, and a small amount of tin, which improves naval brass’ resistance to dezincification, a process where zinc is lost and copper is left. It is a marine, high strength, and corrosion resistant brass that is used for the construction of boats and sea going vessels. Due to the strength and capabilities of naval brass, it is used for the construction of ship propeller shafts, fittings, and turnbuckles. Naval brass is an alpha beta or duplex brass that is stronger and harder than beta or alpha brass.
The original reason for the development of naval brass was for salt water applications or applications that would be exposed to salt water since other brasses underwent dezincification when exposed to salt water. Various alloys were added to alpha beta brass to find an alloy that would prevent the problem. Tin, with a small portion of lead, solved the problem and led to the introduction of naval brass.
Red Brass (CuZn15)
The reddish color of red brass is due to its high copper content, which ranges between 78% up to 96% with the remainder being zinc. It is often referred to as gunmetal brass or 85-5-5-5 brass because of its composition. Red brass is used for plumbing and piping due to its excellent durability, resistance to dezincification, and cracking. Its high resistance to corrosion has led to its use with underground service lines for potable water.
Much like other forms of brass, red brass is suitable for casting due to its strength and machinability. Its attractive reddish color has made it popular as a decorative metal and for hardware use.
White Brass (CuMnZnAlPb)
White brass contains small amounts of magnesium, aluminum, and lead along with its content of copper and zinc. Regardless of the small quantities of these other metals, they are the reason for its white silvery like color and give its corrosion and tear resistance. Sometimes referred to as Dutch metal or German silver, white brass is widely used for the manufacture of jewelry and small musical instruments. It is a very fluid metal with a lower-than-normal melting temperature.
The wide use of white brass for different applications is due to its low cost compared to other forms of brass. Its pleasing appearance makes it ideal for the manufacture of door knockers, cabinet knobs, handles, and fittings. The use of white brass for jewelry is due to how easily it can be formed and shaped into complex and intricate designs.
Yellow Brass (CuZn33)
The zinc content of yellow brass ranges between 20% and 38%, which is the reason yellow brass has its distinct yellowish color. Since it is widely used to produce ammunition casings, yellow brass is often referred to as cartridge brass. One of the reasons that yellow brass is used for ammunition cases is its ability to be cold worked and shaped, a factor that makes it possible for gun owners to save their brass and create their own shells.
Yellow brass can be soldered, brazed, and welded, which adds to its workability. It is corrosion resistant and has good strength but not as substantial as other brass alloys. As with white brass and other brass alloys with a pleasing appearance, yellow brass is used for decorative purposes. Since it can join easily using various techniques, yellow brass is used for pipe fittings and musical instruments.
The various types of brass alloys described above are a small sampling of the many brass alloys that are available. Over the centuries since its first introduction, brass has been developed, perfected, and engineered to be a crucial part of several industries and applications. Its use in the plumbing industry has produced a revelation in reliable and durable methods for transporting water and waste.
Leading Manufacturers and Suppliers
Chapter 4: Types of Copper Used for Forging
As with brass and bronze, copper is one of the earliest metals that was discovered by humans and used for a variety of applications. Due to its ductility and malleability, copper can be shaped, formed, and configured for a wide array of applications. After its initial discovery, it was shaped and formed for tools. In ancient times, copper, like brass and bronze, was shaped using an anvil and hammer. Over the centuries, this type of processing continues to be used in the form of forging.
Forging is chosen as the method to produce copper products and parts since it allows for the creation of high precision components by controlled deformation. The shaping of copper necessitates a small amount of force resulting in less distortion and warping leading to exceptional tolerances and dimensional accuracy.
High Copper Alloys
High copper alloys have a copper content over 94% with small amounts of silver and tin. It is a copper alloy with exceptional strength and durability. The exceptionally high copper content makes high copper highly resistant to corrosion, which is one of the reasons it is so widely used. As with all forms of copper, high copper has exceptional conductivity and can be easily forged. Other alloys that can be added to high copper to increase its properties are zinc, nickel, iron, and aluminum. Regardless of these additions, high copper still maintains its high conductivity.
Leaded Copper
The main alloys of leaded copper are lead and copper with small percentages of zinc, aluminum, tin, and nickel. The addition of lead to copper increases its strength and improves its ability to be forged. The superior machining properties of copper make it exceptionally suited for the forging of precision and accurate shapes. Unlike other forms of copper, leaded copper cannot be used for food applications due to the lead content.
Lead coppers are classified as low lead alloys or machining alloys and high lead alloys. The alloying of lead to copper is an easy process due to the alloying nature of lead, which is widely alloyed with several other metals. Much like copper, lead is malleable, and has electrical conductivity.
Copper Nickel (CuNi)
Copper nickel alloys are forged for salt water used due to their high corrosion resistance. The nickel content of copper nickel ranges between 10% up to 30% for marine applications. A common forged use of copper nickel is seawater piping due to its resistance to the presence of barnacles. The other wide uses of copper nickel include seawater desalination applications, water systems, and fire fighting systems. The dependability, strength, and reliability of copper nickel is one of the reasons for its wide use.
As a part of its strength, copper nickel retains its shape and endurance at temperatures as high as 750°F (400°C). The one feature that makes copper nickel so popular is its lightweight, which is ideal for applications where strength and weight are critical factors.
Nickel Silver
Nickel silver is a copper, nickel, zinc alloy that has been used to make coins, jewelry, and decorative items. The appearance of nickel silver is similar to sterling silver, which has earned it the name of German silver, regardless of the fact that it does not contain any silver. Nickel silver has moderate high strength and resistance to corrosion. It is widely used for food handling equipment, optical and photographic equipment, and musical instruments.
The contents of nickel silver are 7% to 20% nickel and 14% to 46% zinc. The nickel silver alloys with high zinc content are similar to high zinc brass alloys. Like iron, nickel is easily soluble in copper while zinc has limited solubility. The various nickel silver alloys with a zinc content of 32% consist of alpha and beta phases and solidify over a wide range of temperatures. Regardless of its silver appearance, nickel silver alloy resists tarnishing and corrosion more than any other copper alloy, a factor that has led to it being referred to as the anti-tarnish alloy.
Tellurium Copper (TeCu)
Tellurium copper is a form of tellurium bronze that is highly conductive with good machinability. The tellurium content of tellurium copper enhances the machinability, also referred to as its free cutting. The concentration of tellurium in tellurium copper is less than 1% at 0.5% up to 0.75%. Although the addition of tellurium improves the machinability of copper, it still retains its conductivity and its ability to be hot worked. The improved machinability of tellurium copper is similar to the machinability of brass.
The wide spectrum of uses for tellurium copper include welding, plumbing, and electrical applications. It can be easily forged and has good electrical and thermal conductivity, formability, and machinability, its major attribute. The many positive aspects of tellurium copper make it suitable for many industrial and commercial applications.
Chapter 5: Uses for Copper and Brass Forged Products
The forging process ensures the production of durable products since deforming guarantees full density. The wide use of copper and brass forged parts is due to their high thermal and electrical conductivity as well as their ability to accept plating.
Plumbing
Brass can be found in every part of plumbing from pipes and fittings to faucets and handles. It has become the traditional metal for ensuring secure and tight plumbing that is leak proof and stable. As with many aspects of brass, plumbing has depended on the resilience of brass for many years and is the go to alloy when high quality plumbing is required.
Doorknobs and Handles
The strength and visual appeal of copper and brass has made them one of the best alloys used for the manufacture of doorknobs and handles. Since they are antibacterial, their use as doorknobs and handles makes them a method for protecting the health of a home or office.
Bushings
The moldability and flexibility of copper and brass make them ideal for the manufacture of bushings. They do not bind to steel and can fit any wall thickness, flange, sinter, or cylinder. Copper and brass bushings are used for water pumps and electric motors.
Gears
Brass gears are normally forged from yellow brass because of its machinability. Aside from yellow brass, other brass alloys are used for their strength even though they are difficult to machine. The choice of copper or brass for gear making is due to their resistance to corrosion and non-magnetic properties. The copper content makes the forging of gears easier and makes the gears antimicrobial. The gears that are forged from copper and brass are spur gears and gear racks that are used for low loads such as instrument drive systems.
The few copper and brass products listed above are a small sampling of the many parts, components, and implements that rely on the strength and durability of forged copper and brass. The ductility, formability, and adaptability of copper and brass has made forged copper and brass a vital and essential part of several applications.
Chapter 6: Forging vs Casting
Casting and forging are metal working processes that are designed to produce high quality parts and components. The two processes are very different from each other and produce products with different characteristics and properties. The most distinguishing trait that separates the two processes is the use of force, which is prevalent in forging and not found in casting.
Forging
Forging uses a die, pressure, force, and varying temperatures to shape a workpiece into a design or shape. A billet, ingot, or metal sheet is forced into a die by the pressure placed on it by a ram. Forging is classified by temperature, processing type, and the materials it configures. In the forging process, thermal and mechanical energy is applied to an ingot, billet, or sheet of metal. Regardless of the method or type of forging, in all cases, the metal remains in solid form as it is worked and formed.
Casting
In the casting process, the metal is melted in a furnace to reach a molten state. The type and kind of melting process varies in accordance with the type of metal. In the case of copper and brass, which have low melting points, the heating process does not require that much energy. To form a component or part, the molten metal is poured into a hollow cavity and allowed to cool and solidify.
Grain Flow
The main and critical difference between casting copper and brass and forging copper and brass is grain flow. In forging, pressure and force are applied to copper and brass billets to force them to acquire the designed shape. Although it may necessitate successive applications of force, the eventual result is the desired shape. Regardless of the blows and force, the grain structures of copper and brass remain the same and unbroken, which allows them to retain their strength and durability.
This particular factor is completely unlike casting, a process that breaks the grain structure and causes copper and brass to lose their strength once they resolidify. It is this aspect of casting that has to be examined when designing and planning the manufacture of copper and brass parts.
The shaping and reshaping of copper and brass using forging changes their microstructure to disperse alloy concentration and makes the metals denser by removing voids. Unlike casting, forging strengths the mechanical properties of copper and brass to increase their stress level removing any potential failure. Although the shapes produced by forging cannot be as complex as those produced by casting, forging can produce a variety of shapes that have the resistance, reliability, and strength for use in industrial applications.
Metal Forging vs. Metal Casting
Metal Forging
Metal Casting
Structural Integrity
Far superior in strength. Material predictability.
Products are porous and susceptible to breakage.
Tolerance
Less complex geometries.
High level of detail for tight tolerances.
Product Size
Limited in terms of the size and thickness of the metal.
Compatible with a wide range of sizes.
Material Selection
Limited alloy selection.
Any type of metal can be used
Secondary Operations
Secondary operations to refine and finish product to exact specifications.
Few secondary operations
Cost
Cost effective for medium to large production runs.
Cost is dependent on the type of casting
Conclusion
Copper and brass forging is the deformation of the metals for the purpose of manufacturing complex and intricate shapes.
The wide use of copper and brass for forging is due to their exceptional properties. They can be forged into several shapes, which can include complex and intricate ones. The products from forging copper and brass are of the highest quality with excellent dimensional tolerances and bright smooth finishes that compare favorably with other metal worked products.
Most of the typical forging methods are used to work copper and brass. The methods chosen are dependent on the type of copper and brass since each alloy has different characteristics and properties that influence how they can be forged.
Each form of brass can be forged using hot forging to form plumbing fittings, knobs, handles, and other forms.
The initial process for shaping copper, like brass and bronze, was an anvil and hammer. Over the centuries, this type of processing continues to be used in the form of forging.
Leading Manufacturers and Suppliers
Related Posts
Cold Forging
Cold forging is a metal shaping & manufacturing process in which bar stock is inserted into a die and squeezed into a second closed die. The process, completed is at room temperature or below the metal‘s recrystallization temperature to form a metal into a desired shape or configuration...
Forging
Forging is a metal working process that manipulates, shapes, deforms, and compresses metal to achieve a desired form, configuration, or appearance outlined by a metal processing design or diagram...
Open vs Closed Die Forging
In this article, there are key terms that are typically used with open and closed die forging and it is necessary to understand their meaning. Forging is a process in manufacturing that involves pressing, hammering, or...
Rolled Ring Forging
Rolled ring forging is a metal working process that involves punching a hole in a thick, solid, round metal piece to create a donut shape and then squeezing and pressuring the donut shape into a thin ring...
What is Forging?
The ancient art of forging falls into two distinct categories – hot and cold where hot forging has been around for centuries while cold did not begin until the industrial revolution of the 19th Century. Though they are quite different ...
Aluminum Casting
Aluminum casting is a method for producing high tolerance and high quality parts by inserting molten aluminum into a precisely designed and precision engineered die, mold, or form. It is an efficient process for the production of complex, intricate, detailed parts that exactly match the specifications of the original design...
Die Casting
Die casting is a high pressure metal casting process that forces molten metal into a mold. It produces dimensionally accurate precision metal parts that have a flawless smooth finish...
Sand Casting
Sand casting is a manufacturing process in which liquid metal is poured into a sand mold, which contains a hollow cavity of the desired shape and then allowed to solidify. Casting is a manufacturing process in which...
Zinc Die Casting
Zinc die casting is a casting process where molten zinc is injected into a die cavity made of steel that has the shape, size, and dimensions of the part or component being produced. The finished cast zinc product has...
Types of Casting Processes
The casting process is an ancient art that goes back several thousand years to the beginning of written history. The archeological record has finds that document the use of the casting process over 6000 years ago around 3000 BC or BCE...