What are the techniques of metal pressing?

08 Apr.,2024

 

Sheet Metal Pressing Work and Techniques: A Comprehensive Overview

Sheet metal pressing is a highly versatile and widely employed process in the field of manufacturing and construction. It involves the manipulation and shaping of thin metal sheets into various forms and structures, ranging from everyday household items to complex industrial components. This article provides a comprehensive overview of sheet metal work and the techniques commonly used in the United Kingdom, including sheet metal pressing and stamped sheet metal.

Sheet metal pressing encompasses a diverse range of processes, including cutting, bending, forming, joining, and finishing. Each step requires precision and skill to ensure the desired outcome. Let’s delve into some of the essential techniques used in this field:

  1. Cutting Techniques:

   – Shearing: This method involves cutting straight lines in the sheet metal using a specialised machine called a shear. It employs a sharp blade that moves vertically or horizontally to achieve precise cuts.

   – Laser Cutting: Laser technology is commonly used for intricate and accurate cuts. A high-powered laser beam melts or vaporises the metal, leaving a clean and precise edge.

  1. Bending and Forming Techniques:

   – Press Brake: A press brake utilises a hydraulic or mechanical press to bend the metal sheet into the desired shape. It can produce sharp angles, curves, and complex geometries. Sheet metal pressing is a technique commonly employed with a press brake to create specific shapes and contours.

   – Roll Forming: This technique involves passing the sheet metal through a series of rollers to gradually shape it into a desired profile. It is commonly used for creating cylindrical or conical components.

   – Stretch Forming: In this method, the sheet metal is clamped at its edges and stretched over a form using hydraulic or mechanical forces. This technique allows for the creation of contoured shapes with minimal deformation.

  1. Joining Techniques:

   – Welding: Welding is a widely used technique for joining metal sheets together. Processes such as MIG (Metal Inert Gas) welding and TIG (Tungsten Inert Gas) welding are commonly employed in sheet metal work.

   – Riveting: Rivets are used to join two or more metal sheets together by deforming the end of the rivet to create a permanent connection. It provides high strength and structural integrity.

   – Adhesive Bonding: Advanced adhesive technologies enable the bonding of sheet metal components without the need for traditional mechanical fasteners. It offers lightweight and aesthetically pleasing solutions.

  1. Finishing Techniques:

   – Grinding and Polishing: These processes are used to smooth rough edges, remove burrs, and improve the overall surface finish of the sheet metal.

   – Powder Coating: Powder coating involves applying a dry powder paint to the metal surface and then curing it under heat. It provides a durable and attractive finish while offering protection against corrosion.

   – Anodising: Anodising is an electrochemical process that creates a protective oxide layer on the metal surface. It enhances corrosion resistance and allows for the application of decorative finishes.

In addition to these techniques, sheet metal pressing and stamped sheet metal are commonly used in the UK. Sheet metal pressing involves the use of hydraulic or mechanical presses to shape the metal sheet into specific forms or profiles. This technique is often used to create components with precise dimensions and intricate designs.

Stamped sheet metal, on the other hand, refers to the process of creating patterns, designs, or logos on the metal surface using a stamping tool or die. The die is pressed onto the sheet metal, leaving an indentation or raised pattern. Stamped sheet metal is widely utilised for decorative purposes, branding, and identification.

To excel in sheet metal work, skilled craftsmen often rely on specialised tools and equipment. These may include shears, press brakes, rollers, welding machines, plasma cutters, and various hand tools

To excel in sheet metal work, skilled craftsmen often rely on specialised tools and equipment. These may include shears, press brakes, rollers, welding machines, plasma cutters, and various hand tools for measuring, marking, and forming. The availability of advanced machinery and computer-aided design (CAD) software has further enhanced the precision and efficiency of sheet metal work in the UK.

Sheet metal pressing, also known as metal stamping or metal pressing, is a technique widely employed in the UK. It involves the use of a press to shape the metal sheet into specific forms or profiles. The press applies force to the metal sheet, deforming it and creating the desired shape. Sheet metal pressing is often used to manufacture components with complex geometries, such as automotive body panels, electrical enclosures, and appliance parts.

Stamped sheet metal, on the other hand, refers to the process of creating patterns, designs, or logos on the metal surface using a stamping tool or die. The die is pressed onto the sheet metal, resulting in an indentation or raised pattern. Stamped sheet metal can add visual appeal, texture, and branding to various products, including signage, nameplates, and decorative items.

In the United Kingdom, sheet metal work finds applications in diverse industries such as automotive, aerospace, construction, and electronics. It is crucial for the manufacturing of vehicle components, aircraft structures, building facades, HVAC systems, and precision instrument enclosures. Skilled sheet metal workers in the UK possess a deep understanding of different metals and their properties, allowing them to select the most appropriate material for each application.

One significant advantage of sheet metal work is its versatility in working with various metals. Commonly used metals include steel, stainless steel, aluminum, copper, and brass. Each metal offers distinct characteristics in terms of strength, durability, corrosion resistance, and aesthetic appeal. Sheet metal workers must have a sound knowledge of material properties to determine the optimal metal for a specific project.

In recent years, advancements in technology have led to the integration of automation and robotics in sheet metal work. Computer Numerical Control (CNC) machines enable precise and repeatable processes, reducing human error and increasing productivity. Robotic systems can perform tasks such as material handling, welding, and assembly, further enhancing efficiency and throughput.

Quality control is paramount in sheet metal work to ensure the accuracy and integrity of the final product. Skilled craftsmen use measurement tools such as calipers, micrometers, and gauges to verify dimensions and tolerances. Additionally, visual inspections and rigorous testing methods are employed to detect any defects or flaws in the finished components.

In conclusion, sheet metal work is a vital aspect of manufacturing and construction in the United Kingdom. With techniques such as cutting, bending, forming, joining, and finishing, along with specialised processes like sheet metal pressing and stamped sheet metal, skilled craftsmen produce a wide range of products across diverse industries. The integration of advanced technology and the expertise of sheet metal workers ensure the production of high-quality components that meet the requirements of modern applications.

Contact Chasestead Engineering today to find out how we can help with your sheet metal pressing project.

Forming metal sheets with a stamping press

Animation of a power press with a fixed barrier guard

Stamping (also known as pressing) is the process of placing flat sheet metal in either blank or coil form into a stamping press where a tool and die surface forms the metal into a net shape. Stamping includes a variety of sheet-metal forming manufacturing processes, such as punching using a machine press or stamping press, blanking, embossing, bending, flanging, and coining.[1] This could be a single stage operation where every stroke of the press produces the desired form on the sheet metal part, or could occur through a series of stages. The process is usually carried out on sheet metal, but can also be used on other materials, such as polystyrene. Progressive dies are commonly fed from a coil of steel, coil reel for unwinding of coil to a straightener to level the coil and then into a feeder which advances the material into the press and die at a predetermined feed length. Depending on part complexity, the number of stations in the die can be determined.

Stamping is usually done on cold metal sheet. See Forging for hot metal forming operations.

History

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It is believed that the first coins were struck by the Lydians in what is modern-day Turkey in the seventh century B.C. Until 1550, the hammering method of coins remained the primary method of coin-making. Marx Schwab in Germany developed a new process for stamping that involved as many as 12 men turning a large wheel to press metal into coins. In the 1880s, the stamping process was further innovated. [2]

Stamped parts were used for mass-produced bicycles in the 1880s. Stamping replaced die forging and machining, resulting in greatly reduced cost. Although not as strong as die forged parts, they were of good enough quality.[3]

Stamped bicycle parts were being imported from Germany to the United States in 1890. U.S. companies then started to have stamping machines custom built by U.S. machine tool makers. Through research and development, Western Wheel was able to stamp most bicycle parts.[4]

Several automobile manufacturers adopted stamping of parts. Henry Ford resisted the recommendations of his engineers to use stamped parts, but when his company could not satisfy demand with die forged parts, Ford was forced to use stamping.[5]

Over the history of metal stamping, forging and deep drawing, presses of all types are the backbone of metals manufacturing. The processes continue to improve in moving more metal in one press stroke. Press and interconnected automation devices increase production rates, reduce labor costs and provide more safety for workers.

Operation

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  • Bending - the material is deformed or bent along a straight line.
  • Flanging - the material is bent along a curved line.
  • Embossing - the material is stretched into a shallow depression. Used primarily for adding decorative patterns. See also Repoussé and chasing.
  • Blanking - a piece is cut out of a sheet of the material, usually to make a blank for further processing.
  • Coining - a pattern is compressed or squeezed into the material. Traditionally used to make coins.
  • Drawing - the surface area of a blank is stretched into an alternate shape via controlled material flow. See also deep drawing.
  • Stretching - the surface area of a blank is increased by tension, with no inward movement of the blank edge. Often used to make smooth auto body parts.
  • Ironing - the material is squeezed and reduced in thickness along a vertical wall. Used for beverage cans and ammunition cartridge cases.
  • Reducing/Necking - used to gradually reduce the diameter of the open end of a vessel or tube.
  • Curling - deforming material into a tubular profile. Door hinges are a common example.
  • Hemming - folding an edge over onto itself to add thickness. The edges of automobile doors are usually hemmed.[6]

Piercing and cutting can also be performed in stamping presses. Progressive stamping is a combination of the above methods done with a set of dies in a row through which a strip of the material passes one step at a time.

Lubricant

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The Tribology process generates friction which requires the use of a lubricant to protect the tool and die surface from scratching or galling. The lubricant also protects the sheet metal and finished part from the same surface abrasion as well as facilitate elastic material flow preventing rips, tears and wrinkles. There are a variety of lubricants available for this task. They include plant and mineral oil-based, animal fat or lard-based, graphite-based, soap and acrylic-based dry films. The newest technology in the industry is polymer-based synthetic lubricants also known as oil-free lubricants or non-oil lubricants. The term "Water-Based" lubricant refers to the larger category that also includes more traditional oil and fat-based compounds.[citation needed]

Simulation

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Sheet metal forming simulation is a technology that calculates the process of sheet metal stamping,[7] predicting common defects such as splits, wrinkles, springback and material thinning. Also known as forming simulation, the technology is a specific application of non-linear finite element analysis. The technology has many benefits in the manufacturing industry, especially the automotive industry, where lead time to market, cost and lean manufacturing are critical to the success of a company.

Recent research by the Aberdeen research company (October 2006) found that the most effective manufacturers spend more time simulating upfront[clarification needed] and reap the rewards towards the end of their projects.[8]

Stamping simulation is used when a sheet metal part designer or toolmaker desires to assess the likelihood of successfully manufacturing a sheet metal part, without the expense of making a physical tool. Stamping simulation allows any sheet metal part forming process to be simulated in the virtual environment of a PC for a fraction of the expense of a physical tryout.

Results from a stamping simulation allow sheet metal part designers to assess alternative designs very quickly to optimize their parts for low cost manufacture.

Microstamping

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This section is about the industrial manufacturing process. For the ballistics stamping technology and associated laws, see Microstamping

While the concept of stamping sheet metal components has traditionally focused on the macro level (e.g. vehicle, aircraft, and packaging applications), the continuing trend of miniaturization has driven research into micro- forms of stamping. From the early development of micropunching machines in the early to mid-2000s to the creation and testing of a microbending machine at Northwestern University in the 2010s, microstamping tools continue to be researched as alternatives to machining and chemical etching. Examples of applications of sheet metal microstamping include electrical connectors, micromeshes, microswitches, microcups for electron guns, wristwatch components, handheld device components, and medical devices. However, key issues such as quality control, high-volume application, and the need for material research into mechanical properties must be addressed before full-scale implementation of the technology is realized.[9][10][11]

Industry-specific applications

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Metal stamping can be applied to a variety of materials based on their unique metalworking qualities for a number of applications across a wide range of industries. Metal stamping may require the forming and processing of base common metals to rare alloys for their application-specific advantages. Some industries require the electrical or thermal conductivity of beryllium copper in areas such as aerospace, electrical, and the defense industry, or the high strength application of steel and its many alloys for the automotive industry.

Industries metal stamping is used for:

See also

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References

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  • Don Hixon, 1984, December, "Alternative Lubricant Offers Advantages for Stamping", Precision Metal, page 13
  • William C. Jeffery, 1985, November, "Non-Oil Drawing Compounds Make Dollars and Sense", Metal Stamping, pages 16–17
  • Phillip Hood, 1986, Spring, "Environmental Compliance - A Lawn and Garden Manufacturers' Approach to Stamping Lubricants and Environmental Change", Stamping Quarterly, Pages 24–25
  • Pioneer Press, April 27, 1989, Marilyn Claessens, "At 75, IRMCO still a pioneer - Lubricants go down the drain by design", Evanston, IL, page 33
  • Bradley Jeffery, 1991, August, "Environmental Solutions for Metal Stamping", MAN, pages 31–32
  • Robin P. Bergstrom, 1991, November, "Stamping Made Clean(er)", Production Magazine, pages 54–55
  • 1991, February, "Lubricants and Environment Mix", Manufacturing Engineering, pages 52–59
  • Brian S. Cook, 1992, January 6, "Appropriate Technology", Industry week, pages 51–52, 58.
  • James R. Rozynek, 1995, Winter, "Case Study: Converting to Water-Based Metal Stamping Lubricants", Stamping Quarterly, pages 31–33
  • Philip Ward, 1996, July/August, "Water-Based Stamping Lubricant Washes Away Oil-Based Lube Problems", Forming & Fabricating, pages 52–56
  • Matt Bailey, UK, 1997, May, "Non-Oil Lubricants Offer Solvent Solution", Sheet Metal Industries, pages 14–15
  • Chris Wren, UK, 1999, June, "One Out - Oil Out" Sheet Metal Industries, pages 21–22
  • Brad Jeffery, 2003, April, "The Bottom Line - Getting your N-Values Worth", Modern Metals, page 76
  • Brad F. Kuvin, 2007, February, "Forming Advanced High Strength Steel Leaves No-Room for Error", MetalForming, pages 32–35
  • Brad F. Kuvin, 2007, May, "Dana's Giant Lube Leap of Faith", MetalForming, pages 32–33
  • Hyunok Kim PhD, 2008, March "Evaluation of Deep Drawing Performance of Stamping Lubricants with Dual Phase (DP) 590 GA", Part II in III part series, The Center for Precision forming (CPF), The Ohio State University, pages 1–5
  • Brad F Kuvin, January, 2009, "Deep-Draw Automation returns remarkable results", MetalForming, pages 14–15

What are the techniques of metal pressing?

Stamping (metalworking)