A nozzle assembly for a hand piece in an air abrasion system for delivering an abrasive laden air stream to a surface, the nozzle assembly having a connecting member having a channel and being removably mountable to said hand piece, an arcuate conduit member having a channel, the conduit member secured to the connecting member and a nozzle member formed with the channel, the nozzle member mounted within the channel of the conduit member, the nozzle member defined by a tapered channel portion in fluid communication with the channel of the conduit member and a cylindrically-shaped channel portion in communication with said tapered channel portion for directing the abrasive laden air stream in a substantially cylindrically-shaped cross section to the surface to be abraded.