A method of manufacturing a metal cannula is disclosed. The method includes the step of providing a metal cannula having a longitudinal axis and defining a fluid channel. Next, the metal cannula is pressed to substantially close the fluid channel and define a first segment and a second segment. In a next step, the metal cannula is cut to separate the first segment from the second segment of the metal cannula. Each of the first and second segments have a pressed edge. The pressed edge substantially seals the fluid channel and has two pressed corners. Afterwards, each of the pressed corners are cut from the pressed edge of the first segment to define a pair of side openings and a distal blunt edge on the first segment. The side openings are in fluid communication with the fluid channel.