A tool (10) of the "T" type used for milling metal products or other hard materials, such as for making grooves with undercuts on a workpiece holder or the like, comprises a substantially axially symmetric shank (11) comprising an end (18) thereof provided with an appendage (19) and a head (12) of substantially discoidal conformation having a greater diameter than said shank (11) and delimited by two opposite faces (14, 15) of which the face (15) facing said shank (11) comprises a first substantially circular slot (16), arranged with the main axis thereof parallel to the rotation axis of the tool, inside which a second slot (17) is also obtained, also substantially circular, concentric and arranged coaxially to the main slot (16). The head (12) is provided with respective radially arranged holes (23) with the rotation axis of the head (12) coinciding with the axis of the shank (11), where said central channel (21) and holes (23) of the head (12) are configured so that the mutual connection between the shank (11) and the head (12) causes a passage of refrigerant fluid introduced from the base of the shank and delivered by the radial holes (23) of the head (12).