A sandblasting machine is a tool used in jewelry making to create a matte or satin finish on metal surfaces. The machine works by propelling tiny particles of abrasive material, such as sand or glass beads, onto the metal surface. This removes the top layer of the metal, leaving a softer, satin finish. Sandblasting is commonly used to create a uniform surface on jewelry pieces, such as rings or pendants, prior to engraving or setting stones.