Forging University: Forging vs. Casting

Forging University: Lesson #2 – Open Die Forging vs. Casting

Welcome back to Forging University! The second topic in our 5-part discussion compares forging and casting. Before reading, take a quick look back to Lesson #1 and review forging basics. Additionally, you can check out the Anderson Shumaker forging page.

What is Casting?

Casting is the process of heating metal above its melting temperature and then pouring the metal into a mold. The liquid metal takes the shape of its mold. Once it cools, it is released, and it’s ready for further processing. The next steps depend on the metal type itself, as well as the product’s end function. Sometimes forging and machining are included in a cast product’s processing. Casting molds are generally comprised from metal, sand, or ceramic formulas. Steel, bronze, copper, aluminum, lead, iron, and zinc are the most common metals cast today. Casting plays an important part in industrial recycling, as it’s the primary market for scrap metal.

Casting is very different from forging. When forging heats metal, the metal maintains its solidity. Forging uses pressure and force to transform metal into its end shape. Like forging, metal casting is an ancient technology. Cast metals date to 5000 BCE in Mesopotamia (although some historians believe the process began earlier in India or China). Today, metal casting is an important part of manufacturing. Highly complex cast metal parts are found in aerospace, construction equipment, turbines, medical devices, defense equipment, pipes, appliances, automotive, toys, and more.

What are some advantages of casting metal?

• Casting offers a large range of alloy choices that can be easily added in at the molten stage
• It can create complicated geometric parts with very thin walls
• Tooling charges are often less expensive
• Casting can have relatively inexpensive production costs

The Advantages of Forging vs. Casting:

Just like we learned in Forging vs. Fabrication, forging has several distinct advantages compared to casting. Forging offers:

• A reduced chance of voids in the final product
• Continuous grain flow and finer grain size
• Greater wear resistance due to grain flow
• Better fatigue and impact resistance
• Improved microstructure in finished metal

Both forging and casting have their own unique advantages; which process to use ultimately depends on the end role of the component. Of course, we’re partial to forging because it offers so many fantastic advantages, and Anderson Shumaker is a leader in the field.