A clean-out tool system for use with a oil well production tubing extending downward through a casing terminating in a production zone in the well bore, which zone is isolated by a packer and includes flow restricting debris to be cleaned out. A generally vertical, elongated, cylindrical tool body, having a relatively small diameter and a bore therein, is located down through the inner production tubing into the zone located at the end of a tubing string extending downward through the production tubing for communicating fluid pressure to the bore in the body. Four, peripherally spaced, elongated slots extend radially inward into the body with their longitudinal axes aligned with the longitudinal axis of the body and communicate with the bore is the body. An elongated blade is pivotally attached in each slot to the body, movable from a first configuration wherein the blade is positioned vertically within the slot, and a second, expanded configuration positioned radially outward in the zone. The blade is pivoted to its second configuration responsive to increasing pressure in the tubing string and is limited in its movement by the degree of an upper cam face onthe blade preventing any cutting engagement between the clean-out blades and the interior surfaces of the casing. The tubing string is moved longitudinally and rotated, rotating and moving the blade in its second configuration within the zone, loosening debris which is then removed by fluid circulation. The blades are provided in sets for different expansion sizes.