Abstract: For cutting sheet metal or other work by means of a jet of water containing abrasive particles, an abrasive water jet nozzle assembly is provided to which there are separately supplied highly pressurized water and an abrasive suspension. The abrasive suspension is such that abrasive particles with an average size of up to 100 microns are held in suspension in water. The abrasive suspension is introduced into the ejected water by virtue of a partial vacuum created in the nozzle assembly by the pressurized water. The nozzle assembly directs the resulting mixture as an abrasive water jet against the work for cutting thereof. Preferably, the abrasive water jet is recovered for recirculation back to the nozzle assembly as an abrasive suspension of controlled abrasive concentration. Various constructions of the nozzle assembly and various recovery systems are also disclosed.