ROTARY CUTTING TOOL

PROBLEM TO BE SOLVED: To efficiently feed the cutting solution to a work cutting point of a circular tip 3 by using the cutting solution as the liquid in a rotary cutting tool in which a spindle assembly 2A formed by inserting a spindle 4 in a circular tip 3 is stored in cartridge case 2B fitted to a tool fitting hole 1a formed in a tool holder 1 so that both ends of the spindle 4 are inserted in a pair of bushes 71 and 72 in the case 2B, and the spindle assembly 2A is pivotably supported by the fluid pressure by feeding the fluid to pockets 7a and 7b for a radial bearing and a thrust bearing formed on the bushes 71 and 72. SOLUTION: An opening 6d facing an end face of the spindle 4 is formed in the cartridge case 2B, and cover members 81 and 82 for guiding the cutting solution flowing through the opening 6d toward a work cutting point of the circular tip 3 are provided outside the cartridge case 2B.