The Sand Casting process has been a key element in manufacturing for thousands of years and still accounts for approximately 70% of all castings. Whether Sand Casting is the best option for the production of a particular component will be dictated by considerations such as the required geometry, performance, alloy choice, production run, tolerance within specification and surface finish.
Sand Casting is a highly flexible and versatile process with casting weights at NovaCast ranging from a few grams to over 4 tonnes. Tooling costs are relatively low, and moulds are cheap to produce making the process particularly suitable for low volume production although sand casting is also used for longer runs and batch production of components. It can be used to cast virtually every metal ranging from low melting-point non-ferrous alloys to specialist Stainless Steels. Complex internal structures can be created through the use of internal cores and shaped parts are confined only by the imagination of the designer.
There are, however, several limitations with sand casting which may dictate the use of alternative processes. Sand casting in general, and green sand casting in particular, provide lower dimensional accuracy than other casting processes. This may be acceptable if further machining is required anyway although the amount of machining required is generally higher with sand casting. Similarly, the surface finish is usually inferior to processes such as die casting or investment casting. This is often not an issue and components are supplied in the as-cast state or further machined if the rough-cast state as cast finish is not acceptable.
NovaCast’s foundry in Melksham specialises in non-ferrous castings using both Sand and Gravity Die Casting while our Far Eastern facilities focus on Investment and ferrous castings. We are, therefore, able to advise on the most appropriate casting process and alloy to suit performance requirements. There have been many instances where we have lowered production costs and improved performance simply by changing the process or converting complex fabrications to castings.