In the table below, you will find a comprehensive list of the alloys we employ in the sand casting process as well as their physical properties. Exceptions regarding alloys utilized in this process may be made based on the quantity of castings requested by the customer, job size, etc.
The Green Sand Molding process is commonly used in the casting of non-ferrous alloys, which include aluminum and brass.
The term "green sand" is known, principally because of the moisture content within the sand. The sand undergoes a "mulling" process in which water, clay, and chemical additives, that act as binders, are blended with the sand. This results in a compound which is suitable for the sand molding process.
This prepared sand mixture is then compressed and compacted around the pattern at specific pressures and temperatures to ensure that the mold will maintain it's shape throughout the remainder of the casting process and therefore, take on the shape of the desired casting.
Sometimes the design of the casting entails internal passageways being formed into the mold. This is done by using sand cores which are made of a similar sand mixture. The cores are strategically placed to form the necessary passageways in the casting. The two halves of the mold are subsequently closed and the molten metal is poured into the cavity and left to solidify.
After solidification has taken place, the sand mold is dumped and vibrated until it is released from the casting. The finishing process can then be completed by cutting, grinding, machining, powder coating, etc.
As a general rule, Green Sand Molding produces castings with dimensional tolerances in the .030 - .060 inch/foot range (1/32 to 1/16 inch/foot). The surface roughness of green sand castings usually ranges between 250 to 2000 microinches.