Understanding Metal Material Selection in Deep Drawing

Deep drawing is one of the most common metal forming processes that is used in manufacturing. It shapes flat sheet metal into hollow, contoured parts. The process works by pushing a metal blank into a die cavity using a punch. It creates items like kitchen sinks, automotive body panels, and industrial containers.

The material selection plays a major role in how the part forms and performs. Different metals behave in different ways during deep drawing. Some are easy to form without tearing or wrinkling. Others may need extra steps to prevent defects. If you choose the wrong material, even a well designed part can fail in production or worse, in the field.

What Makes a Metal Good for Deep Drawing?

Not all metals are suitable for deep drawing. The best ones have a few key traits:

• High ductility (they can stretch without breaking)
• Low yield strength (they start to deform without needing too much force)
• Good thickness consistency (to avoid weak spots)
• Strong grain structure (for uniform behavior across the blank)

The forming process puts metal under a lot of stress. If the material doesn’t bend and stretch in a controlled way, you’ll get cracks, wrinkles, or thinning. That’s why material selection starts with understanding how a metal responds under pressure.

Low Carbon Steel

Properties and Formability

Low carbon steel, also called mild steel, is one of the most popular materials for deep drawing. It contains less than 0.25% carbon, which gives it excellent ductility and softness. It’s easy to form, holds its shape well, and doesn’t spring back much after forming. These traits make it reliable in high volume runs.

Drawing quality (DQ) and deep drawing quality (DDQ) grades are available. These types of steels are processed so they have a fine grain structure and consistent thickness.

Common Uses

• Automotive body panels
• Electrical enclosures
• Steel drums
• Appliance housings

Impact on Final Product

Low carbon steel gives good dimensional control and surface finish. It’s also cost effective, which matters in competitive industries like automotive. However, it’s prone to rust, so it often needs coating or painting after forming.

Stainless Steel

Properties and Formability

Stainless steel is harder than mild steel but still widely used in deep drawing. The most common grades for drawing are 304 and 316. These austenitic stainless steels offer good corrosion resistance and moderate flexability.

They require more force to form and can work harden faster. This means the material gets stronger and has less stretch as you shape it. You may need multiple draws or lubrication to prevent cracking.

Common Uses

• Kitchen sinks
• Food processing equipment
• Medical trays
• Chemical containers

Impact on Final Product

Stainless steel offers durability and a clean, corrosion resistant surface. That makes it ideal for applications that need hygiene or chemical resistance. But forming costs are higher due to the added force and tooling wear.

Aluminum

Properties and Formability

Aluminum is lightweight, corrosion resistant, and easy to form. It has good ductility and doesn’t need as much force as steel. However, it can wrinkle more easily and may not hold tight tolerances without extra steps.

Common Uses

• Cookware
• HVAC components
• Automotive heat shields
• Lighting housings

Impact on Final Product

Aluminum reduces weight, which helps in fuel efficiency and shipping costs. It also doesn’t rust, so it often doesn’t need coating. But because it’s softer, it’s more prone to surface damage. The forming process needs care to avoid tool marks and distortion.

Copper

Properties and Formability

Copper has excellent ductility and conducts heat and electricity well. These qualities make it easy to deep draw. It forms smoothly and can stretch a lot without tearing. However, it’s expensive and can oxidize if not protected. It also has a tendency to stick to tooling, so having lubrication is important.

Common Uses

• Electrical terminals
• Plumbing parts
• Decorative hardware

Impact on Final Product

Copper is a good choice when electrical or thermal performance matters. The soft surface can show scratches, so final appearance must be managed carefully. Oxidation can be an issue unless you finish it with plating or coating.

Brass

Properties and Formability

Brass is a combination of copper and zinc. It offers better strength than copper while still being easy to form. It has good flex and a smooth surface, which helps reduce friction during drawing.

Some grades are more suitable than others. Cartridge brass (around 70% copper, 30% zinc) is known for excellent deep draw properties.

Common Uses

• Ammunition casings
• Clock parts
• Decorative components
• Plumbing fittings

Impact on Final Product

Brass offers a balance of strength, appearance, and formability. It has a gold color, which can reduce or eliminate the need for the finishing of decorative parts. It iss more expensive than steel or aluminum, so it’s used when function or appearance justifies the cost.

Nickel Alloys

Properties and Formability

Nickel-based alloys are used in extreme environments where corrosion and heat resistance are critical. They are tough to form. High strength and low ductility make them a challenge in deep drawing. These materials often need intermediate annealing steps. Having lubrication and special tooling are also required.

Common Uses

• Aerospace engine parts
• Medical components
• Chemical processing equipment

Impact on Final Product

Nickel alloys offer superior performance, but the cost and forming difficulty are high. They are not used unless the application demands it. The final product is durable and stable under heat, and is resistant to corrosion, but forming it requires experience and expert process control.

How Material Choice Affects Final Product Quality

The metal you choose affects more than just cost. It influences each stage of production and the performance of the part after it leaves the plant.

Forming Behavior

If a metal doesn’t stretch evenly, you get thinning or tearing. If it wrinkles too easily, cosmetic and structural issues follow. Choosing a material with the right balance of flexability and strength prevents these problems.

Surface Finish

Some materials scratch easily. Others need coating or plating. You may need to protect the surface during forming, especially if appearance matters. Smooth materials like brass or stainless often give a better finish straight off the tool.

Dimensional Stability

Materials with springback can shift out of shape after drawing. If tolerances are tight, you will need to allow for this. Low carbon steels have low springback. Stainless and aluminum may need correction.

Tool Wear

Harder materials wear out tools faster. That can add to the cost and downtime. You might need special coatings or materials for your dies and punches when working with stainless, nickel, or brass.

Post-Processing

Some metals weld easily and others won’t. Some need coating for corrosion, others don’t. Knowing how the material fits into your full deep drawing process helps avoid surprises later.

Final Thoughts

Picking the right metal for deep drawing is more than just checking if it will fit in the die. You need to think about how it does during forming, what it will cost to process, and how it will perform in the field. Using good materials will make production easier and reduce scrap. They also make the final part more reliable.

If you are working on a new deep drawn product, talk to your supplier about the specific grades and how they respond in your process. Even small changes in composition or finish can make a big difference in results.