Passing through a small-diameter orifice, the water forms a coherent jet of water，where a metered amount of granular abrasive is drawn into the water stream. The mixture of water and abrasive particles passes through a special ceramic mixing tube, and the resulting abrasive/water slurry exits the nozzle as a coherent cutting stream of abrasive particles traveling at very high speed.Abrasives cut only when they successfully reach the material. 

The abrasive’s mesh must be the correct size for the orifice to avoid clogging. Eighty-mesh garnet is most universal between nozzle sizes, whereas 50-mesh garnet is much coarser and is typically used with . Using a narrower nozzle with 50-mesh garnet will increase the likelihood of clogs. For smaller nozzles used for high-precision , a mesh of 120 or higher is optimal.

For pure waterjet applications performed without abrasives, more pressure may lead to faster cutting. In fact, the smaller diameter of the jet that comes from a high-pressure system may be more effective in water-only cutting applications, such as food products or foam rubber. In abrasive waterjet cutting systems, however, the abrasive does the cutting, not the water. Instead, the water accelerates small abrasive particles in a coherent stream that can erode the material being cut.