Green Sand castings are castings that are made of green sand moulds or wet sand. Don’t be surprised if we tell you that the sand is neither green in colour nor the mould uses any greensand or greenish colour sandstone. Rather, the sand is termed ‘green’ because of the moisture content present in it such as green wood before the sand dries out when molten material is poured into a mould. The reason for the stickiness of sand moisture with the sand is that when moulds are made, the clay is mixed in the sand. When sand and Bentonite clay is mixed together it gives out strong moulds that can be produced on an automated assembly line.

Green sand castings are applicable in a number of engineering products such as ship part, pump housings, flywheels and engine blocks. For instance almost 42% of all cast parts in the US are manufactured with green sand moulds. No-bake, the next most popular casting type, comparatively is 40%. Because moulds can be made quickly with green sand casting through automated machines, it is economical and the most preferred choice for producing medium to high volume castings. Also, the automated processes help produce an appreciable number of moulds fast at an affordable cost.

In addition to being comparatively inexpensive, green sand castings make pretty large castings. Green sand castings as sizeable as 7000 pounds are quite common, though usually they remain in the 1-500 pound weight bracket. A disadvantage of green sand castings is that they come with a cap in terms of size often limited by compaction needed to make the mould. Therefore, for large castings, it is better to go with other casting methods. For instance, no-bake castings offer improved giant sized castings. No-bake castings are known to produce as large as 100,000 pounds or 50 pounds.