Nassguss

Nassguss is a German term that translates to "wet casting" in English and refers to a casting process where the mold is made of a wet material, typically sand. This method is a variation of sand casting and is commonly used for producing metal parts of various sizes and complexities. In the traditional sand casting process, sand is mixed with a binder and rammed around a pattern to create the mold cavity. For nassguss, the sand is used in a relatively unbonded or loosely bonded state, and the moisture content plays a crucial role in maintaining the mold's integrity during the casting process.

The key characteristic of nassguss is the use of a damp sand mixture. This moisture content helps the sand particles adhere to each other sufficiently to hold the shape of the mold cavity when the pattern is removed. However, the moisture must be carefully controlled. Too much moisture can lead to steam explosions when the molten metal is poured, causing defects and safety hazards. Too little moisture results in a weak mold that collapses. The sand is typically rammed around the pattern to create the mold, and then the pattern is withdrawn. Molten metal is then poured into the cavity. After solidification, the casting is removed from the sand mold.

Nassguss is favored for its cost-effectiveness and relatively simple setup compared to more sophisticated casting methods. It is suitable for a wide range of ferrous and non-ferrous alloys. The finish of the casting is often coarser than that achieved with other methods, and secondary machining may be required to achieve desired surface quality or dimensional accuracy. Despite these limitations, nassguss remains a widely used and important technique in the foundry industry for producing a significant volume of cast components.