Smith Castings LLC  
Smith Castings, LLC
 Questions? +1 800.417.6484

How we do it
While the basic process of casting has been around for many years, we believe that people make the difference. We are not a highly automated foundry seeking high quantity runs. Our process requires personal care of every part we produce. From producing the cores, molds, melting and pouring, to finishing and inspection, our team makes the difference. Taking pride in everything we do.

The basic process
Core Making-Oil Sand, Pep-set, and Special Cores

Most cast parts require cores to be added to the mold to make the shape of the "Inside" of the part. There is a main ingredient (the shell or oil core sand), spices (chemical additives in the sand), a mold to give the cake its shape (the wooden pattern box) and an oven to bake it. The cores play an important role in the quality of the interior surfaces of the part. We also make pep-set cores, as well as purchase special cores for special work.

Making the core: The basics
• Using a custom part pattern that is made in-house or provided by the customer, the process of making a core begins.
• Using chemically treated shell or oil core sand, the wooden pattern box is filled, then repeatedly compacted.
• Once thoroughly compacted, the core is then carefully removed from the pattern box and taken to the oven.
• The core is then baked in the oven until it harneds.
• Once removed, the core is smoothed and then set aside.
• The core is now ready for the next stage in production - making the mold.

Mold Making - Green Sand "Squeeze"
and Chemical "No Bake" bond.

Our process offers two different types of Molds, each having their distinct advantages. Squeeze molds are made by ramming the sand and pouring within a few hours. Whereas, No bake molds can be made ahead and buffered for an indefinite period of time. Different parts specifications determine which type of mold is best suited for the job.

Green Sand “Squeeze” Molds

The green sand line uses a wet (hence, the term "green") mixture of sand, clay, water, sludge, and chemicals. The sand is poured around a pattern that sits in either the top (cope) or bottom (drag) side of the mold. A cavity and gate system are created by compacting the sand around the pattern. The mold may include a core, a heat resistant filter and other elements, such as sprues (channels for the molten metal) or risers (which allow gas to escape).
Dry Sand “No Bake” Chemical Molds


The "no bake" line uses dry sand bonded with materials other than clay, usually a quick setting resin and catalyst. The molding sand is poured into a flask and held until the resin solidifies, usually at room temperature. The no bake method offers a larger casting than squeeze, where squeeze molds are limited. We handle Mold weights up to 400lbs.

Melt and Pour Casting

A Smith Castings pour is both art and science. First, the melt is performed in a furnace. Here, we melt the "charge" or the metal and alloy materials that make up that melt. Various elements (e.g. nickel, manganese, etc.) may be added to the base iron or steel during the melt to reach the desired chemistry - a range specified by the customer, industry, or our own internal standards. Refining is done to remove harmful gases from the molten metal and helps avoid casting defects.
Once the mixture is ready and in the transport ladle, which is mounted on a flexible trolley system, we need to move fast, as the composition may "fade" or deteriorate over time. The flow rate into the mold must also be held steady, to help ensure the molten metal reaches its desired destination inside. Once poured, the molds are moved aside to cool. Sometimes weights are placed on top of the molds, to help prevent the mold from expanding or separating. The cool time depends on the overall weight of the mold. Once the metal hardens and cools, it's officially a cast.
Sand Removal - Shakeout and Blast
Shakeout - Once the molten metal cools and hardens, it becomes a cast. However, it still needs to be removed from the green sand mold and cleaned up a bit before it heads off to the final step: finishing. The cleanup takes place in either the shakeout tray or a tumbler, depending on the size of the part. Here, through intense vibration, any remaining sand is removed from the cast part.

For "No Bake" chemically bonded molds, the process is more manual using a hammer to break up the mold, remove the parts, and load this type of sand in the re-claimer. Then, prior to finishing, the parts with gates are sent to shot blast to remove any remaining particles of sand.

Shakeout: The basics
• Once the mold cools and hardens, it becomes a cast. The next step is to remove the cast from its mold, usually by breaking the sand casing.
• The cast is then placed into a shakeout machine or tumbler, where the sand is removed through intense vibration.
• At this point, the cast may still have heads, runners, gates, and risers attached. These are the remaining parts of the channels through which the molten metal traveled.
These pieces are cut out or knocked off with a hammer.
• Once the sands are removed, the part is taken to the final step of production - finishing.
Finishing - Torch or Cut, Grind, Chip and Spool, Blast

After removing the sand particles for the molded part, finishing begins by removing the gating from the cast components. We torch cut, grind disk remove, or air arc, the mold gating from the parts. The parts are put in our oven for solution heat treat. Then we shot blast them to insure that the grinders and chip and spool bench grinders are able to clean up exterior and internal surfaces. Each different type of part requires it's own finishing specifications. This requires an experienced, flexible team to insure that the parts are finished to meet the customer specifications. After chip and spool, we again, process the parts through the oven to prepare them for final shot blast and inspection. For parts that require special heat treating, we partner with reliable, outsource suppliers. Most times, these parts return to our plant for final blast, inspect, and ship.

Depending on customer requirements, we may provide other services as well. Painting to prevent corrosion and improve visual appeal is common, as well as some basic assembly or welding.

Finishing: The basics
• Finishing involves grinding, sanding, or machining the component in order to achieve a desired dimensional accuracy, physical shape, or surface texture.
• Removing the remaining gate material, called a gate stub, must be done prior to any final machining.
• Some foundries provide other services, such as heat treatments or painting, which helps prevent corrosion and improves the visual appeal of the finished product.
• Once the finishing part of the process is done, the part moves on to testing and inspection. After that, it's finally ready to ship!

Inspection

Before any order ships, we will scrutinize the quality of the work - to your standards, as well as ours. We follow American Society for Testing and Materials (ASTM) guidelines as well as our own best practices, developed over four decades. In house and on site, we have the ability to perform a variety of common chemical and physical certificiations. These may include normalization, physical, microstructure, spectrometer, and heat treatment tests.

Alternatively, for analyses that require more in-depth or complicated examinations than we are able to perform on the premises, we often send out parts for other procedures, including magnaflux, fluorescent penetrant, dye penetrant, X-ray, radiographic, and ultrasonic tests. Once the parts are certified, they are ready to ship.

Pattern Work
For the majority of our work the customers own the patterns. We have a pattern workshop to maintain and repair the patterns. Often, the customer requires (or at our suggestion) modifications to the patterns. We have experienced people to insure the well being of the customers property. When a customer needs a new part that requires a pattern to be made, we can make some in our own shop, or send the work out to our supply partners to build. these are typically quoted separately from the castings. Our experience helps in the design to give the best outcome.

Pattern Storage
Our customer pattern storage is maintained and organized on site.