What is Cold Stamping and How Can It be Used?
Cold stamping , also called cold pressing, is a metalworking process that uses a cold or unheated hammer to imprint a pattern on the surface of a workpiece. In other words, it is a type of non-heat-treatable surface finishing process in which the properties of the metal are changed by applying pressure to the surface of the material and leaving an image. Cold stamping is an alternative to heated stamping—a method that uses heated dies and hammers. Cold stamping has several advantages over heated stamped parts: no special tools or equipment are needed, it can be used on any metal part that doesn’t exceed −20°F, costs less than heating, is quicker and simpler to set up, does not require skilled operators, and produces better results with less scrap. It can also be used on thin materials which cannot be effectively stamped when using heat processes.
What Processes Are Used in Cold Stamping?
Cold stamping can use a variety of processes including: – Embossing – the process of creating a three-dimensional pattern on the surface of a metal by applying pressure to the metal surface and then lifting the press while the metal is still in the shape of the die. The raised pattern is either polished or left as-is. – Raised Significantly – when the stamping is significantly higher than the metal’s surface, the excess metal is removed after stamping. – Rolled or engraved texture – a texture that is rolled onto the metal surface. – Rolled edge or Rolled edge and engraved – an edge is rolled and then engraved. – Electroformed coatings – a thin coating of metal is deposited on the part by electroplating. – Etching or oxidation – the metal is etched to change the color or to create a decorative pattern.
Advantages of Cold Stamping
– No heat needed – Cold stamping doesn’t require heating the metal, which reduces energy consumption. – Options for a wide variety of metals – Cold pressing can be performed on a wide variety of metals, including copper, stainless steel, and other non-heat treatable alloys. – Little to no tooling investment – Cold pressing doesn’t require specialized equipment, so there is little to no investment in tooling. – No special labor training needed – Cold pressing doesn’t require highly trained (or paid) operators. This makes it ideal for organizations with low labor costs, such as SMEs. – Lower cost than heat stamping – Cold stamping is less expensive than heat stamping, especially when the costs associated with tooling are considered.
Disadvantages of Cold Stamping
– Thinner materials can bow or deform – Thin materials that are stamped will bow or distort when stamped. – Can’t achieve good surface finishes – Cold pressing can’t achieve the same level of surface finishes as heat stamping. – May require secondary finishing operations – Cold stamping may require additional operations, such as deburring, to remove excess metal or to smooth out the edge of the part. – No extended textures – Textures that are significantly raised are difficult to create with cold stamping.
Key Steps in Cold Stamping
– Select the metal and determine the desired thickness. Once you’ve decided on the type of metal, you’ll need to determine the acceptable thickness of the parts. It’s important to keep in mind that the thicker the metal, the more difficult it will be to stamp the design. – Design the part and create a die. The next step is to create a design and then create a die to stamp the image onto the metal part. You’ll want to keep in mind that the thicker the metal, the smaller the die should be. – Select the stamping process. The next step is to decide which type of stamping process you’d like to use. While pressed texture and rolled texture are used for raised texture. – Stamp the part. The final step is to stamp the part, remove the excess metal, and then finish the edges as needed. – Inspect the part. The last step is to inspect the part to make sure it meets the design requirements.
Cold stamping involves no heating of the metal parts, so it doesn’t require the energy or equipment needed for heat stamping. However, it may take longer to stamp the design than for parts heated in a press. Cold pressing requires less skill and less investment than heat stamping. The equipment is less complex and there are fewer safety issues associated with cold pressing. As a result, it’s best for smaller companies that don’t need the high production rates associated with heat stamping.