1- What Is Sand Casting?
Sand mold casting is a tranditional but also modern casting process. It uses green sand (moist sand) or dry sand to form the molding systems. The green sand casting is the oldest casting process used in history. When making the mold, the patterns made of wood, metal or plastic should be produced in order to form the hollow cavity. The molten metal then pour into the cavity to form the castings after cooling and solidification. Sand casting is less expensive than other casting processes both for mold development and unit casting part.
The sand casting, always mean the green sand casting (if no special description). However, nowadays, the other casting processes are also use the sand to make the mold. They have their own names, such as shell casting, furan resin coated sand casting (no bake type), lost foam casting and vacuum casting.
2 - How Are Sand Castings Made?
We have different casting types for your choice. Part of the optional process for your project will be the selection of the casting process that will best serve your needs. The most popular form is sand casting which involves making a replica of a finished piece (or pattern) that is compressed with sand and binder additives to shape the final metal castings. The pattern is removed after the mold or impression has been formed, and the metal is introduced through a runner system to fill the cavity. The sand and the metal are separated and the castings are cleaned and finished for shipment to the customers.
3 - What Is Sand Casting Used For?
Sand mold castings are widely used in a diverse industries and mechanical equipment, especially for the large castings but with small demanding quantity. Due to the lower cost of development of tooling and pattern, you can invest a reasonable cost in mold. Generally speaking, the sand casting are the first choice for the heavy machineries such as heavy duty trucks, rail freight cars, construction machineries, valves, pumps and hydraulic systems. Especially, the ductile iron sand castings are used more and more for modern industries.
4 - What Are The Advantages of Sand Casting?
✔ Lower Cost due to its cheap and recyclable mold materials and simple production equipment.
✔ Wide range of unit weight from 0.10 kg to 500 kgs or even bigger.
✔ Various Structure from simple type to complex type.
✔ Suitable for production requirements of various quantity.
5 - What Metal & Alloys Does Your Sand Casting Foundry Mainly Cast?
Generally most ferrous and nonferrous metals and alloys could be cast by sand casting process. For ferrous materials, gray cast iron, ductile cast iron, carbon steel, alloy steel, tool steel along with the stainless steel alloys are most commonly poured. For nonferrous applications, most Aluminum, Magnesium, Copper-based alloys and other nonferrous materials can be cast, while Aluminum and its alloy are the most widely cast via sand casting.
6 - What Casting Tolerances Could Your Sand Castings Achieve?
The casting tolerances are divided into Dimensional Casting Tolerances (DCT) and Geometrical Casting Tolerances (GCT). Our foundry would like to talk with you if you have special request on the required tolerances. Here in the following are the general tolerances grade we could reach by our green sand casting, shell mould casting and no-bake furan resin sand casting:
✔ DCT Grade by Green Sand Casting: CTG10 ~ CTG13
✔ DCT Grade by Shell Mold Casting or Furan Resin Sand Casting: CTG8 ~ CTG12
✔ GCT Grade by Green Sand Casting: CTG6 ~ CTG8
✔ GCT Grade by Shell Mold Casting or Furan Resin Sand Casting: CTG4 ~ CTG7
7 - What Are Sand Molds?
The sand molds mean the casting molding systems made by green sand or dry sand. The sand molding systems mainly cover the sand box, spures, ingates, risers, sand cores, mold sand, binders (if have), refractory materials and all other possible mold sections.