The Ultimate Guide to Deep Drawing: A Comprehensive Overview
Deep drawing is a mass-production process that can form sheet metal into a desired shape. It uses a mechanical press to push flat sheet metal into a die cavity, forming it into the desired shape.
The resulting workpiece or product is often called a deep-drawn part.
In this guide, you can easily understand the Deep Drawn Stamping Process and at the end, I will leave a small tip to help you manufacture custom deep-drawn parts.
Read Time: 7 Minutes
By: Tuling Engineering Team
Tuling is a leading manufacturer of custom deep-drawn parts. We specialize in deep drawing dies and offer cost-effective solutions.
What is Deep Drawing?
In deep drawing, sheet metal parts are drawn into the desired shape using a die. A mechanical punch or press, pushes the flat sheet metal through a die into its die cavity, forming a completely different drawn shape.
The resulting sheet metal part has no parting lines, seams, or cuts. In the deep drawing process, the original sheet metal thickness remains the same. The forming process only draws the sheet through a die without stretching it.
Metal cans are a great example of deep-drawn parts.
What Is The Deep Draw Stamping Process?
Deep drawn metal stamping is a metal stamping process that produces cup-shaped, open end cylindrical shapes, and complex hollow geometries using progressive dies, to draw the starting metal blank into the desired shape.
Deep drawn stamping is a serial process where different dies incrementally mold the sheet metal.
Let’s look at the step by step deep draw process.
Step 1. Creating the Blank
Deep drawn metal stamping begins with creating a small rectangular metal blank.
A large sheet stock is fed into the metal stamping machine, where it is cut to a smaller square or rectangular blank.
Step 2. Bending
In most deep draw metal stamping processes, the die simultaneously forms the blank into a cup. The sheet of metal bends into the die and the blank holder applies a force to allow this bending without any slippage.
Step 3. Straightening
After the bending stage, the blank holder moves to release some of the sheet metal to allow it to flow into the die forming a cylindrical shape. The straightening process creates the shell wall.
The height to diameter ratio controls the wall thickness and for higher ratios, repeated deep draw stages are needed to avoid wall thinning.
Step 4. Final Shape
This three stage metal stamping process is repeated until the final shape through different dies is achieved.
Deep drawn stamping can produce a number of straight, curved or contoured shapes.
Benefits of Deep Draw Stamping
Deep drawing is a high volume production process. Deep draw stamping can produce hundreds of complex parts or even thousands of smaller finished parts every hour.
There are many advantages of deep drawing that can help you choose manufacturing components by this metal stamping process.
- High Production Speed: Deep drawn stamping is extremely efficient for the open end part manufacturing. The mechanical press can stamp hundreds of parts everyday and the only tool change is a die.
- Seamless Finished Part: Deep drawn components do not have seams or parting lines. There are no microholes because the entire metal part is a single piece. For water-tight parts like gaskets, deep draw stamping can be used.
- Cold Forming: Deep drawing is a cold working process. All metal stamping is done at near room temperature this produces hardened and stronger deep drawn components.
- Reliable (with no errors): Deep drawn stamping is a highly repeatable process and requires no change during production runs. It eliminates the chance of error.
- Complex Geometries: Deep draw metal stamping can produce extremely intricate shapes. This process is widely used to make car parts and filters.
- Low Cost Production: Tuling can produce deep drawn stamping products at extremely low costs because of its repeatability and high volume.
- Material Selection: Deep draw stamping can use a range of raw materials. It is possible to deep draw raw material sheets like
- aluminum alloys
- copper
- hardened steel
- carbon steel
- Titanium
- Reduced Material waste: Deep draw essentially has no material cutting. Almost all of the starting blank is formed into the final shape without unnecessary waste.
Where Can I Use Deep Drawing?
Deep draw metal stamping can be used in a wide array of applications and industries. Before delving into the applications of deep drawing, consider what can be deep drawn?
Metals that can be cold rolled can be deep drawn. This means any metal that can be cold worked or metals that can be rolled into sheets to make the first deep drawn blank are ductile enough for deep drawing process.
Deep drawing has become a modern manufacturing unit and almost all industries utilize the ease of production of formed parts.
Automotive Industry
Deep drawing can produce complex components that are widely used in the car industry. Car body panels are entirely made of deep drawn components.
Airplane Production
Many airplane engine components like housings are made from deep drawing.
Appliance Parts
Home appliances like washing machines, refrigerators and ovens have panels and bodies made from drawing.
Things To Consider When Deep Drawing Parts
Deep draw is a large production process. Before you can start deep drawing your parts, there are many precautions and calculations that need to verify your sizing. Many things including compression, wall thickness, uniformity are at play.
Now I will share a small key to help you understand how you can deep draw parts.
- Drawing Ratio
Drawing ratio is the ratio of the blank and punch or stamping tool’s diameter.
D=Db/Dt
Drawing ratio can help you decide whether your material can be drawn without any defects like shrinking.
Drawing ratio in deep drawing must be less than 2.0 - Reduction
Reduction is another parameter that tells you the change in diameter from the starting blank to your first draw or final draw.
It is the difference of blank diameter and punch diameter as a ratio of blank diameter. This ratio can help you decide which material you can choose for your drawing process.
Note: Die radius is often not the final radius of your part. This is because the shaped portion often has rolled edge which reduces the final radius or diameter. - Thickness to Diameter Ratio
This measures any reduction in the wall thickness starting from the blank to the final drawn part.
It is often calculated as the thickness of starting blank divided by blank diameter.
Custom Deep Draw Manufacturing at Tuling
Tuling has decades long experience in custom deep draw manufacturing. Our engineers are ready to help you decide on your materials, process and die part design for your specific needs.
Reach us for a quick chat to help you decide which deep draw service is best for you and how many deep draw runs will make the most efficient and cost effective service.
FAQ
What is a shell wall in deep draw metal stamping?
Shell wall is the straight portion of the deep drawn part that starts from the bottom and ends at the open end of your workpiece.
What is a blank holder?
Blank holders in deep drawing is a small clamp that holds the sheet and controls the flow of the metal into the die for uniform wall thickness.
