Precision metal fabrication is used in a variety of industries, and more and more parts for different industries are now being manufactured through metal fabrication. With the growth of metalworking, it is important to understand the proper way to manufacture parts. Depending on the needs of the product, there are two different methods of part machining processes: deep drawing and stamping.
Deep drawing is a method of shaping a sheet of metal to create a smooth surface with precise measurements. Stamping, on the other hand, involves hitting the sheet metal with a die to form it into the desired shape. Deep-drawn parts are usually more accurate and have a smoother surface than stamped parts. Some of the following information will help you decide whether deep drawing or stamping is better for your needs.
Table of Contents
What is Deep Drawing?
In deep drawing, a series of dies are used to stretch a sheet of metal into a desired shape repeatedly. This produces a part with a smooth surface and very accurate dimensions. Complex shapes can be made more quickly, accurately, and efficiently using the deep drawing process. Deep-drawn parts last longer than stamped parts. This is because they are subjected to more stress and pressure during production.
Advantages of Deep Drawing
- Powerful for making a large number of high-quality products
- Capable of complex designs
- Flexibility of materials
- Produces parts with more uniform wall thickness
Disadvantages of Deep Drawing
- Requires specialized tools and equipment
- Higher tooling costs than metal stamping
- Not suitable for making small quantities
What is Stamping?
Metal stamping is a versatile manufacturing process that can produce many identical parts very quickly. This metalworking process stamps flat metal through a die to form it into a desired shape. Stamping, coining, bending, embossing, flagging, and piercing are a few common stamping processes. They all use different dies to perform various stamping operations. Stamped metal parts are usually less accurate and have rougher surfaces than deep-drawn parts.
Advantages of Stamping
- Simple to use and less difficult to operate
- Higher processing efficiency
- A wide range of metals can be used to produce parts of different shapes and sizes.
- Ideal for mass production of parts
Disadvantages of Stamping
- Produces more scrap
- Not suitable for very complex or customized parts
- It may require a large amount of labor
How to Choose the Best Process for Your Project?
Here are a few things to consider when choosing between a deep drawing or stamping process for your project:
- Complexity of the Part: If your project has deeper complex parts. Then deep drawing may be the better choice. Stamping may be better suited for flat parts with simple shapes.
- Production Volume: If you need to produce large quantities, stamping may be the quicker and cheaper method. For small production runs or patterns with lots of small details, deep drawing will cost more.
- Type of Material: Look at what material you want to use. Some metals are better suited to the deep drawing process and some are better suited to the stamping process.
- Cost Considerations: Consider both initial setup costs and ongoing production costs. For small orders, deep drawing may be too expensive. For large orders, stamping can save even more.
- Required Strength: If you need a strong part, deep drawing may give you better mechanical quality. This is because it makes the metal stronger and more durable during the stretching process.
The Difference Between Deep Drawing and Stamping
The following points illustrate the differences between deep drawing and stamping.
Accuracy
The accuracy of a deep drawn part can be judged by the thickness of the metal and the roundness of the inside corners. In most cases, deep-drawn parts are more accurate than stamped parts. Very high dimensional accuracy can only be obtained with single-point deep drawing. The outer surface of a stamped part is always rougher and the dimensional accuracy is not as good as that of a deep-drawn part.
Surface Finishing
The surface of a deep-drawn part is usually smoother than the surface of a stamped part because there is only one deformation process in the manufacturing process. The manufacturing of stamped parts requires two processes (forming and embossing), which makes the surface finish more difficult and rougher.
Adding an embossing method to a formed piece of metal can make it look better. But it does not make the structure better. This is because it just makes the material thicker and does not change its shape or size. The embossing process does not give the part any solid support.
Bending
In most cases, the two-piece bending method is used to create sharp corners in deep-drawn parts. The best type of extrusion die to use for deep drawing is the single-point type because it provides the most accurate measurements and bending angles.
For many useful parts, stampings cannot make the tight bends or angles required. However, it is possible to stamp some parts into the desired shape and then move them to another assembly fixture where they are formed by bending. In this way, no additional work is required and high quality is maintained.
Production Costs
Since the deep drawing process requires two presses, the equipment cost is higher than the stamping process. We need to use the main press for deep drawing and then the second press for stamping. However, since deep drawing parts are more accurate than stamping parts, less work is required after the deep drawing part is made. This reduces costs because less scrap and labor is required.
Material Thickness
In most cases, deep-drawn parts are thinner than stamped parts. This is because the metal flows more freely during the molding process. The material is dispersed again and therefore does not build up on the walls of the mold. This results in a more regular distribution. This redistribution also improves the flow of metal particles throughout the part, resulting in a stronger part.
If you want to make sure that the strength stays the same, deep drawing works better because it transfers the material. Parts of uniform thickness can also be manufactured by stamping. However, stamping is less stable and it is difficult to get the thickness just right.
Design
When making a deep-drawn part, the fabricator must keep in mind that the deep-drawing process is limited by the degree of bending and stretching of the sheet metal. To ensure that the part can be deep drawn, these limitations must be taken into account when calculating the wall thickness, angles, and other details of the part.
Deep drawing is not a good way to make complex parts with tight bends. This is not the case with stamping, so it can be used in more situations without having to consider the fabrication process.
Ease of Manufacturing
High-volume production lines can make deep-drawn parts quickly and easily. The process is simple and the tools don’t need to be changed as often. Stamped parts, on the other hand, are more difficult to manufacture and usually require longer lead times. As a result, waiting times are longer and production costs are higher.
Mass Production
The deep drawing process is most effective when large quantities of products need to be produced. It is a quick and easy way to make a large number of products in a short period of time. Another way in which the stamping process is used for mass production is to better control the surface finish of the part. Because the stamping process is slow, it cannot produce a large number of products at the same time and is not suitable for producing a large number of products at one time.
Strength
Deep-drawn parts are stronger than stamped parts because the metal is stretched during the deep-drawing process. This makes the metal more flexible, which makes it stronger. The stamping process, on the other hand, does not stretch the metal as well and therefore the metal is less flexible.
Since stamped parts are not flexible, they are more likely to break when subjected to higher pressure. One of the major advantages of deep-drawn parts over stamped parts is that they are stronger. This is the best choice for uses that require great reliability.
Appearance
One of the problems with deep drawing is that it can sometimes change the shape of the surface by adding wrinkles, stretching, or breaking. While you don’t always see these deformations, they can make things look less aesthetically pleasing. The stamping process leaves the surface smooth and unaltered in shape. Stamped parts are more attractive based on appearance alone.
Formability
Deep drawing is a formable method because it makes it easy to mold sheet metal into complex shapes. Stamped parts are more difficult to form than deep-drawn parts because the metal does not stretch and is less elastic. Parts that require deep drawing have higher formability than stamped parts.
Application Considerations
Parts requiring high strength but lightweight are more likely to be strengthened during deep drawing. Deep-drawn parts have a thinner cross-section than stamped parts but do not lose any mechanical characteristics.
Deep drawing is also a better way to make parts that need to be rust-proofed because it gives the part a better surface finish and more accurate measurements. Stamped parts are not as good if you want to make parts that are lightweight but strong or won’t rust.
Volume
For mass production, deep drawing works better. When only a small number of parts need to be made, stamping is better. This is because stamping is better suited for small production runs than drawing, and costs less.
Drawing has a higher setup cost but can make a large number of parts quickly, making it ideal for mass production. Stamping uses cheaper tools and does not require a lot of work to make a large number of parts.
Materials
Many drawn parts are made from steel, aluminum, and copper alloys. Stamped parts, on the other hand, are mostly made from mild steel or alloy steel. However, this is not always the case and both methods can be used with many different materials to make many different parts.
Shape
The final shape of the part depends on whether it is formed by deep drawing or stamping. Deep-drawn parts have a thinner cross-section than stamped parts, so they can be made into more complex shapes. In addition, deep-drawn parts have smaller tolerances than stamped parts.
Manufacturing Process
The molding process for stamped parts is generally a one-step process. In contrast, the forming of deep-drawn parts involves many steps, such as designing the mold, preparing the material, punching, stretching, cutting, and inspecting. This means that stamped parts can be produced faster than deep-drawn parts, resulting in significant cost savings.
Since stamping uses less electricity than deep drawing, it also requires less machine maintenance, which reduces the running costs of the process.
Post-processing
Once a stamped part is made, it can be used immediately as it does not require any additional processing. This is not the case with deep-drawn parts, which require several post-processing steps such as deburring, surface polishing, and painting. As a result, the deep drawing process requires more processing time and costs.
Lubricants
It is possible for lubricants and liquids to get on deep-drawn parts. Therefore, it is important to use materials that will not be damaged by these. One way to do this is to harden or coat the material, or to use materials such as plastics and ceramics that are less susceptible to water and other chemicals.
Summarizing
When deep drawing metal, a punch and die are used to stretch the metal into the desired shape. In contrast, in stamping, a point and anvil are used to shape the metal. Stamped parts are more difficult to shape than deep-drawn parts and can only be produced in small quantities. In the deep drawing process, the metal is stretched, which makes the part stronger than a stamped part.
Stamped parts are not as strong as deep-drawn parts because the metal is not stretched. Deep drawing is best suited for design elements that require very easy molding. In most cases, deep-drawn parts cost more than stamped parts. However, their higher strength-to-weight ratio and corrosion resistance make up for this.