Foundry work today is incredibly involved and complex – from pattern creation and core making to the actual casting process and subsequent quality control. However, the complexity of the process is how foundries like Tazewell Machine Works are able to produce such a wide range of custom castings with intricate external geometries and internal cavities.
Virtually any unique shape, part feature, and cross-sectional geometry can be cast with superior quality here at Tazewell Machine Works. Our molds and cores are formed exactly according to your specifications, which reliably produce and reproduce the end product.
For new foundry customers or anyone unfamiliar with custom casting services, we’ve put together a basic guide to what goes on behind the scenes.
An Overview of the Foundry Process:
Pattern Creation – We begin the process by having a custom pattern created – essentially a replica of the desired final casting. Patterns can be made from many different materials such as wood, plastic, or easy-to-work metals to minimize your time and costs spent in the tooling process. We work closely with our partner pattern shops to get patterns manufactured to exact customer specifications. The pattern shop performs the 3D modeling then builds the pattern based on our guidance of layout and orientation.
Core Box Creation – Once we have the pattern, we have a core box based on the negative shape of the casting’s internal geometry. Core boxes are typically made from metal and designed to split apart so that we can easily remove the core once it is cast.
Core Sand Preparation – As the name suggests, sand casting relies on core sand, which is a specially formulated mixture of sand, binder, and additives that we use to provide strength and stability to the core. The sand mixture is typically made with high-quality silica sand and a binder such as clay or resin, optimized for the high heat and pressure experienced during the casting process.
Core Making – When it comes time to
make the core, we pack sand into the core box using specialized methods to achieve optimal compression. Typically, the sand is blown into the core box using compressed air, rammed and tightly packed into the core box by hand or machine, or mixed with a resin binder and shot into the core box under high pressure.
Curing – Once the core is formed in the core box, we put it through a special curing process to harden the binder and ensure the core maintains its shape. Depending on the application and binding materials curing is sometimes performed at room temperature, while other castings require heat curing.
Core Assembly – After the core is cured, we remove the cores from the core box and assemble the components into the casting mold. We have to precisely position the core within the mold cavity to create the desired internal features of the final casting.
Molding – The cores and supporting components such as gating and risers are placed inside the mold cavity. The mold is closed, then it’s finally time to pour molten metal into the mold cavity. The molten metal inside the mold cools and solidifies, taking on the exact shape of the cavity and the cores.
Casting Removal – Once the metal has solidified, we carefully remove the casting from the mold. The cores are then broken away from the casting, leaving behind the final part with its desired internal features.
Quality Control and Inspection – Of course, meticulous quality control is baked into every step of our foundry process. Once the casting is removed from the mold, it’s the perfect opportunity for close inspection and additional quality assurance. We ensure that castings meet all customer specifications, and check closely for any manufacturing errors or defects.
Machining – Many custom castings require additional complex machining operations to achieve the desired end shape, geometry, and special part features. For these products, our integrated machine shop for
custom machined casting solutions provide you with a streamlined path to your end products.
Quality American Foundry Services and Custom Castings Since 1945
Tazewell Machine Works provides superior American foundry services rough and machined castings. Our products are backed by a robust ISO 9001:2015 certified quality control system and over 75 years of excellence delivered from our foundry right here in Pekin, Illinois.
