The gravity sand casting is a rotor, which was used in the field of automobile. The material is aluminum alloy, and the finish is shot blasting. For the industrial sand casting, NOQ is 1000 PCS and the lead time is 45 days. The general tolerance of the aluminum sand casting is CT-6, the surface roughness is Ra 6.3. JST is an OEM manufacturer of industrial aluminum sand casting, we could also do the additiona machining and finish treatment. If there is any inquiry for gravity aluminum sand casting, please do feel free to contact us for quotation and I believe JST will be your qualified supplier.