Sandblast nozzle are what makes every sandblasting machine able to preform work. They direct and concentrate the air and media stream through a fixed orifice and then onto the workpiece. Blast nozzle size is one of the most important factors to a successful blast operation, every blast nozzle must be sized according to the available amount of air coming into the blast machine from the air compressor. A nozzle to small may potentially clog if large grit media is being used. A nozzle to large may overload the air compressor and could lead to embedment of media into the workpiece. A nozzle that is to large for the air compressor will not work as intended and will destroy production, material economy, life of wear components, and potentially harm the air compressor. A worn out nozzle will cause the same poor results as a nozzle that is oversized. Actual nozzle measurements can be taken by using a specialty tool, punches or drill bits. The "actual size" of any blast nozzle is the point inside the nozzle with the smallest internal diameter. Nozzle material can make or break a blast operation, with highly aggressive media, such as aluminum oxide, ceramic nozzles will wear out almost immediately. Boron carbide nozzles are the hardest and longest lasting nozzles.