A Guide to the Deep Drawn Stamping Process

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Guides

Posted by

Bob Longo

Posted on 

April 2, 2020

Posted at 

7:24 pm

What is Deep Drawn Stamping?

Metal stamping – sometimes called metal pressing – is a cold-forming process used to produce a wide range of parts and products from coil strip metal. As a cold working process, it is usually performed at room temperature with room temperature materials. Stamped components range in both size and shape, from simple parts 0.08 to 2.0-inches in diameters with a maximum length of 3.0 inches for various industries.

Deep drawing – also referred to as deep drawn or deep draw stamping – is a form of metal stamping that generates seamless round enclosures (i.e., cases) that are at least as high (or taller) as they are wide. Examples of typical deep drawn components include cans, housings, and other containers. They are particularly well-suited for use in demanding environments where reliability and tight tolerances are critical, such as in the electrical and electronic technology industries.

Overview of the Deep Drawn Stamping Process

The deep drawn stamping process employs the use of radial tension-tangential pressure to form metal into the desired shape and size. A series of specialized dies and punches decreases the diameter and increases the length of the blank – i.e., the flat metal disc – according to the part design. The resulting piece is cylindrical or hollow-shaped with straight, tapered, or combination sides.

A standard deep drawn stamping operation includes the following steps:

• Designing the part. Every stamping operation begins with a design for the intended end product. Once the design is complete, the manufacturer can determine what dies and punches are required to achieve the shape and size of the component. Some factors to keep in mind include the dimensions of the part, the customer’s requirements, and which methods to employ.
• Determining the material. Based on the above, they then determine which material suits the part and production specifications. Typical materials used in deep drawn stamping operations include aluminum, brass, copper, stainless steel and low carbon steel.
• Performing the stamping operation. Once the part design and material are set, the manufacturer can move on to the stamping phase. Using the press and tooling (i.e., punches and dies) they identified during the design phase, they gradually form the blank into the part. Each station – i.e., draw or reduction – decreases the diameter and increases the height of the material, with a single part generally taking five or more stations to achieve the desired shape and size. The number of draws or reduction required depends on the part design and the type and thickness of the stamping material.

Benefits of Deep Drawn Stamping

As a manufacturing method, deep drawn stamping offers several advantages to industry professionals. While it may not be ideal for every part or production need, such as the manufacture of complex components, it does provide the following benefits:

• High accuracy and tight tolerances. The deep drawn stamping process is highly precise and repeatable. Its use of custom-tailored tooling enables manufacturers to produce parts to near-exact dimensional tolerances and maintain consistent dimensions between parts and from one batch to the next. Together, these qualities ensure higher overall production quality, lower error rates, and better customer satisfaction within the delivered products.
• Few process steps. Deep drawn parts require fewer operations to produce as they do not require any cutting or assembly. Additionally, their high precision, combined with their accommodation of automation and other rapid production methods, necessitates less manual labor requirements.
• Fast process speeds. Compared to other manufacturing equipment, punch presses generally offer the fastest processing speeds. This quality is ideal for producing large quantities of a single part or product.
• Large production volumes. Deep drawn stamping is ideal for large volume production projects. Once the dies and punches are ready, the presses can perform operations near-continuously with fast speeds, little downtime, and minimal operator involvement.
• Low production costs. While the tooling for a deep drawn stamping may require a significant initial investment, once it is purchased or created, operations can proceed with little downtime or additional equipment costs. When used for high-volume production runs, the per-unit cost goes down even more, especially given the lower manual labor demands and faster processing speeds. Companies can further minimize the cost of production by converting to the deep drawn process versus alternative manufacturing methods (i.e. screw machining, cold heading).
• Seamless parts. Deep drawn parts are produced from a single blank that is neither cut nor fused. The resulting piece has no seams or joined edges, making for a watertight or airtight component.  
• High hardness and strength. During deep drawn stamping operations, metals experience work hardening. This phenomenon results in a crystalline structure that offers little movement, translating to extremely hard and durable parts.

Additional Processes Employed During Deep Drawn Stamping Operations

Deep drawn stamping operations often incorporate other forming and finishing processes to achieve more complex and/or finished parts and products. Some of the typical processes employed include:

• Adding beads, ribs, and flanges: Industry professionals often add geometric features – such as beads, flanges, and ribs – to stamped parts to impart strength and rigidity to areas that may be too weak or flexible. When carefully incorporated into the part design, these features can allow for the reduction of a part’s thickness without sacrificing structural integrity.
• Bulging: The bulging process uses specialized expansion punches to expand the walls of a part. The expansion can target the entire piece or a section and create asymmetrical or symmetrical shapes.
• Coining: The coining process employs the use of closed dies that confine or restrain the entirety of the workpiece to produce intricate features to tight tolerances.
• Curling: The curling process forms a rolled edge at the open end of the workpiece.
• Dimpling: The dimpling process creates an indent in the workpiece for use in future flush riveting or bolting operations.
• Embossing: The embossing process creates raised or depressed designs on the metal.
• Extruding: Extrusion – also called hole flanging – is a process that draws a flange around a hole in the workpiece.
• Hole forming: Holes can be formed using traditional, extruding, and piercing punches.
• Ironing: The ironing process reduces the thickness and smoothens the surface of the part’s walls.
• Marking: The marking process is used to add identifying characters, such as designs, numbers, or words, to the workpiece.
• Necking: The necking process reduces the diameter of a particular section of a cylindrical workpiece.
• Notching: The notching process creates cuts – i.e., notches – along the edge of the workpiece for future mounting or clearance demands.
• Threading: Taps, dies, or a wheel and arbor set create threads along a portion of the part.
• Trimming: The trimming process cuts scrap material off a partially or fully finished part.

Precision Metal Stamping Services

At Peterson Manufacturing, we provide both deep-drawn stamping and precision stamping conversions. Our team of ISO 9001:2015-certified experts are able to work with parts that range in diameter from 0.08-2.0 inches (2-50 mm) with a maximum length of 3.0 inches (76mm.) With each and every press, our top priority is to ensure consistent, high quality results for our customers.