According to one implementation, a hole finishing tool includes a reaming cutter and a holder. The reaming cutter has a first detaching structure. The first flow path for ejecting cutting oil is formed inside the reaming cutter. The holder has a second detaching structure. The second detaching structure is detached from and attached to the first detaching structure. The second flow path for supplying the cutting oil to the first flow path is formed inside the holder. The holder has a shank. The shank is held by a tool rotating device. The holder has a sliding portion. The sliding portion has no back taper. The sliding portion is inserted into a positioning bush and slid inside the positioning bush. The sliding portion has a concave portion for storing lubrication oil.

According to one implementation, a hole finishing tool includes a reaming cutter and a holder. The reaming cutter has a first detaching structure. The first flow path for ejecting cutting oil is formed inside the reaming cutter. The holder has a second detaching structure. The second detaching structure is detached from and attached to the first detaching structure. The second flow path for supplying the cutting oil to the first flow path is formed inside the holder. The holder has a shank. The shank is held by a tool rotating device. The holder has a sliding portion. The sliding portion has no back taper. The sliding portion is inserted into a positioning bush and slid inside the positioning bush. The sliding portion has a concave portion for storing lubrication oil.