Broaching tool

A broaching tool comprising an elongated tool body having a plurality of spaced ribs disposed generally transverse to the longitudinal body axis, each said rib defining an arcuate path of at least 45.degree. with each succeeding rib having a larger diameter than the preceeding rib, a plurality of cylindrical cutter discs mounted along each rib, each disc having an end face providing a cutting edge disposed about the periphery of the end face, each disc being positioned with its end face disposed within 1.degree.-15.degree. of coincidence with the longitudinal axis of said body, the discs along each rib being staggered circumferentially with respect to the discs of the next adjacent rib such that the paths of successive cutter discs overlap, said discs being arranged to broach a hole having a radius at least three times the radius of the individual cutter discs, each disc projecting beyond the outer face of the rib and being rotatably indexable about its longitudinal axis to bring successive cutting portions into cutting position.