At New England Soda Blast we use several types of media when blasting to have the least amount of friction and heating on the part being cleaned, this avoids warping the parts. Thin sheet metal is mostly blasted using Baking soda,all other metal is checked prior to blasting and the proper media is used. We have from very fine silica free products brought from Canada to very heavy media called Patriot Blast. In general media goes from 000 to 0 (triple zero to zero) where 0 is the heaviest. As an example cast iron is mostly blasted with very heavy media and a hood of a car is blasted with baking soda. In the end regardless of the type of metal you bring it will be dealt with knowledge of 13 years in business.