From structural components and aerospace parts to consumer goods and decorative items, versatile metal casting processes create complex shapes from molten metal through high-volume production. As casting is compatible with a broad spectrum of material options, you can select the one that best fits your product requirements, part design, application, and budget. Learn more about the techniques and common materials involved in casting to help you choose a metal with confidence.
About Casting Metal
Metal casting encompasses several controlled processes of pouring molten metal into a hollow mold so that, as it cools, the material hardens into a preconfigured shape.
Types of Metal Casting Processes
Examples of metal casting techniques include:
- Sand casting. Utilizing a sand mold is the most common metal casting technique.
- Die casting. With a metal mold, or die, foundries can generate complex parts with precision.
- Investment casting. Investment or lost wax casting employs a refractory material-coated wax pattern as a mold.
- Centrifugal casting. By pouring metal into a mold as it turns, the motion causes material flow in an outward direction. The metal solidifies against the mold’s walls as it cools.
- Continuous casting. Also with a moving mold, this casting technique uses the ongoing motion to create parts in lengthy, continuous sections.
Advantages of Casting
Each casting method has its own benefits and ideal uses, but they share the following key advantages:
- Complex shapes. Casting processes can create geometrically complex and intricately detailed parts that other manufacturing techniques cannot.
- Large order volumes. The casting method is perfect for high-volume production of uniform components.
- Cost-effectiveness. A side benefit of being able to produce large quantities is that casting can be an economical manufacturing choice, lowering per-part costs.
- Material options. With versatile metal casting, you can choose from an array of different materials to suit your needs.
Which Type of Metal Is Used in the Casting Process?
To determine which type of casting material is right for you, select a material that will deliver the required properties for your product. For example, evaluate a material for its strength, weight, resistance capabilities, price, and workability. Ferrous metals like steel and iron can lend your product impressive strength and durability, while non-ferrous varieties such as aluminum and zinc tend to offer good machinability.
Before we get into the top three types, we’ll first discuss other common metal casting materials:
- Stainless steel. This steel variety is strong, inert, and hygienic, making it ideal for anything from structural components to food processing and healthcare equipment.
- Abrasion resistant cast iron or chrome and nickel hard irons. These iron varieties are made with higher concentrations of the alloy elements to enhance wear characteristics, used in wear liners, pumps, piping, and other applications that need great wear properties.
- Brass. Malleable brass offers good machinability. Its corrosion resistance makes it appropriate for plumbing fixtures, while its pleasing aesthetics lend it to applications ranging from doorknobs to musical instruments.
- Bronze. This copper-tin alloy is a strong metal variety, resisting general wear and corrosion. It has both functional and aesthetic uses, from gears and bearings to artistic sculptures.
- Zinc. Compatible with the die casting process for its low melting point, zinc is good for hardware, vehicle parts, and even children’s toys.
Top Three Metal Materials Used in Casting
Which metals, then, are your top metal casting options?
1. Aluminum
Among the lightest and most abundant of metals, aluminum has a great strength-to-weight ratio and — given its superior machinability — can help reduce your production costs. Being lightweight and corrosion-resistant makes it highly popular for aircraft and vehicle parts in which weight reduction and durable construction are of great importance. Aluminum is available in many different alloys, each one unique and possessing its own benefits, so it’s a versatile choice with both indoor and outdoor applications.
2. Steel
Steel is primarily prized for its strength. While it can also be used in vehicle parts, steel components are reliably durable enough to handle structural and industrial equipment projects, as well. Similarly to aluminum, steel is flexible in its applications because of its numerous available alloys, such as stainless, carbon, and alloy steel. However, when discussing the material itself rather than its machining process, steel is a more affordable material option than aluminum or metals like copper.
3. Cast Iron
One of its primary benefits where metal casting is concerned is that cast iron has good fluidity when it’s in its molten state, facilitating part production in complex shapes. Cast iron parts can handle applications that will expose them to friction as the metal offers exceptional resistance to wear. This tough material is also thermally conductive, allowing parts like engine blocks to conduct heat. As for pricing, cast iron typically beats out both aluminum and steel, making it another economical choice.
Quality Castings for All Metal Types by Midwest Metal
At Midwest Metal Products (MMP), our foundry provides quality engineering, casting, heat-treating, and finishing services. We’re dedicated to adding value for our customers, enhancing product reliability, and reducing part count. Contact us to learn about our casting services and which metal is right for your project, or request a quote today.