If you have shopped for metal parts, you have probably heard the terms foundry and casting used as if they mean the same thing. They do not. A foundry is a facility, a working shop where solid metal is melted, poured, and turned back into finished components. Casting is the specific process of shaping that liquid metal by pouring it into a mold and letting it solidify. In other words, casting is one of the main things a foundry does, but a foundry is more than a single process. Getting that distinction right helps you ask better questions and buy better parts.

At C.L. Dews & Sons Foundry, we have been pouring metal in Hattiesburg, Mississippi for generations, so this is a conversation we have often. This guide walks through what a foundry actually is, what casting really means, how the two work together, and what separates a shop that produces sound, reliable parts from one that ships porous, cracked castings that fail in service.

Foundry and Casting: What Each Term Actually Means

What Is a Foundry?

A foundry is a manufacturing facility built around the melting and pouring of metal. It houses furnaces to bring iron, steel, aluminum, or bronze up to a liquid state, a molding area where the shapes are prepared, a pouring floor, and a cleaning and finishing area where the raw part is shaken out, ground, and inspected. A full-service operation like ours also runs a pattern shop that builds the tooling and a machine shop that takes the rough casting to final dimensions. So the foundry is the ecosystem: the building, the equipment, the crew, and the accumulated know-how that turns a drawing into a physical part.

What Is Casting?

Casting is the forming process itself. You melt metal, pour it into a cavity shaped like the part you want, and let it cool until it solidifies into that shape. The cavity is the mold, and the pattern is the master model used to create that cavity. Casting is one of the oldest manufacturing methods on earth, and it is still the most efficient way to produce complex shapes, internal passages, and heavy sections that would be wasteful or impossible to machine from a solid block. When someone says they need a part “cast,” they are describing the process. When they say they are sending it to the “foundry,” they are naming the place where that process happens.

How Foundry and Casting Work Together in Practice

Walk a job through our shop and the relationship becomes obvious. It starts long before any metal is melted. A pattern is made to match the part, allowing for the small amount the metal will shrink as it cools. That pattern is packed in sand to form a mold cavity, and cores are set in place to create any hollow interior features. Only then does the casting step happen: metal is melted to the right temperature, treated and checked, and poured in a controlled stream that fills the cavity cleanly.

After the metal solidifies and cools, the mold is broken open, the part is shaken out, and the gates and risers used to feed metal into the mold are removed. From there the casting moves to grinding, heat treatment if the alloy calls for it, and machining to final tolerances. Every one of those steps lives inside the foundry, but only one of them is the casting itself. That is the heart of the foundry and casting relationship: casting is the moment of shaping, and the foundry is everything that makes that moment produce a part you can trust.

Long before any metal is poured, a pattern is packed into molding sand to form the cavity that will shape the part.

The Core Casting Processes Used in a Modern Foundry

The right choice depends on the part. A high-chrome cast iron crusher liner headed for a quarry is a natural sand casting job because of its size and the wear-resistant alloy involved. A small, detailed component in the thousands might justify a die. Part of what a good foundry does is steer you toward the process that fits your volume, your material, and your budget, rather than forcing every job through the one method it happens to own.

What Separates a Quality Foundry From a Basic Casting Shop

Here is the part most buyers never see. Two shops can pour the same alloy into the same shape and get very different results. A casting can look perfect on the outside and hide voids, trapped oxide films, or gas porosity that only reveal themselves when the part cracks under load. The failure of a single step can ruin an otherwise good casting, which is why disciplined foundries treat the whole pour as a chain of controlled decisions rather than a splash of hot metal.

None of this is visible in a quote. It shows up years later in whether the part is still doing its job. When you evaluate a Hattiesburg foundry and steel fabrication partner, or any supplier, the questions worth asking are about melt control, gating design, and inspection, not just price per pound. For a broader look at industry standards and best practices, the American Foundry Society is a solid neutral resource.

Choosing the Right Foundry and Casting Partner

Once you understand that the foundry is the place and casting is the process, choosing a supplier gets simpler. You are not just buying a casting. You are buying the melt practice behind it, the molding discipline around it, and the finishing and machining that follow. A shop that keeps all of that under one roof controls quality at every handoff, which is exactly why we run our foundry, fabrication, and machine shop together rather than shipping half-finished parts between vendors.

That integration matters most on the parts that cannot fail: crusher wear parts for mining and aggregate operations, bridge components for infrastructure, and custom castings for the machinery that keeps a plant running. When the same team pours the metal, grinds it, and machines it to spec, there is no finger-pointing when something needs to be right. If you are weighing custom metal casting for an industrial application, that continuity is the difference between a part you install and forget and one you spend the next year troubleshooting.