Provided is a T-shaped tool (10) configured by fastening a head (30) having cutting blades (36, 38) to a cylindrical shank (20), wherein the shank (20) is made of cemented carbide and has a tapered male thread (24) formed at a tip end portion thereof, the tapered male thread (24) becoming smaller in diameter toward the tip end, and the head (30) is made of steel and has a tapered female thread (50) formed therein, the tapered female thread (50) coming into engagement with the tapered male thread (24).