Described is a nozzle assembly that includes a body component defining a center axis. The nozzle assembly also includes an energy beam channel and substantially collinear with the center axis. The energy beam channel has an inlet portion and an outlet portion oriented to pass an energy beam therethrough. At least one side-feeding powder tube extends through the body component at an angle with respect to the center axis. The side-feeding powder tube discharges a powdered material into a focus point of the energy beam. The angle is selected to generate a powder concentration spot diameter that is about twice a beam focus point diameter of the energy beam focus point.