Bore boring combination cutting tool

The utility model provides the utility model discloses a railway freight car walks the bore boring combination cutting tool of capable part side bearer supporting seat spot facing work, including tool bit 10 and handle of a knife 20, the anterior segment of tool bit 10 is spiral bit 11, and back end 12 is tertiary coaxial round platform stairstepping structure, and the round platform diameter is reduced to the anterior segment orientation by 20 ends on the handle of a knife in proper order, and the border punishment of every grade of round platform do not sets up welding outer blade group 1, 2 and 3, and every group blade is the 2 -4 sword, along round platform circumferential edge along evenly distributed, for improving life, cutter anterior segment spiral bit 11 adopts removable connected mode with back end 12, in the processing, at first processing out the aperture by cutter anterior segment spiral bit 11, then by 1, the 2 and 3 hierarchical reamings of the outer blade group of welding on the back end 12, finally reaching to complete the processing of, the machining precision is by the outer trajectory control that follows of final outer blade group 3, the utility model provides a prior art need the problem of twice change processing cutter, realized one -pass processing, improved machining efficiency and machining precision.