A tool handle assembly includes a molded adapter bonded to the end of a handle shaft, which adapter includes a generally cylindrical cap portion and a generally tapered frustoconical portion that surrounds the handle shaft adjacent to the cap portion. The handle assembly is inserted into a lower entrance of a tapered eyehole of a tool head such that the frustoconical portion of the adapter engages a portion of the eyehole. In one preferred form, the cap portion of the adapter includes external barbs. A pair of arcuate wedges having interior teeth are inserted between the cap portion of the adapter and the tool head and bear on the major axis of the tool head. The teeth of the wedge cooperate with the barbs of the adapter to secure the wedges in place. In another preferred form, the adapter includes a pair of slots into which wedge inserts are driven to expand the cap portion of the adapter and thus secure the tool head to the handle assembly. Again, the adapter includes barbs within the slots, and the wedges include teeth which cooperate with the barbs to secure the wedge inserts within the slots.