Disclosed herein is a hair clipper blade set comprising a lower blade including a forward edge with a series of teeth extending therealong, upper and lower surfaces extending from said forward edge, and a threaded bore extending between the upper and lower surfaces, a movable upper blade including a forward edge with a series of teeth extending therealong, an upper surface, and a lower surface supported by the upper surface of the lower blade, a spring member for supporting and biasing the upper blade against the lower blade for linear movement of the forward edge of the upper blade parallel to the forward edge of the lower blade, which spring member comprises a forward portion including a forward end positionable against the upper surface of the movable blade, and a rear portion parallel to and spaced apart from the upper surface of the lower blade behind the movable upper blade and having therein an aperture, and a tension adjustment screw extending through the aperture, having an enlarged head engaging the spring member, and having an outer end releasably secured in the threaded bore, and further including, in the outer end, a recess facilitating rotation of the screw in the bore by manipulating a tool removably extending into the bore from the lower surface of the lower blade.