Broach cutting using Drillco cutters means you can produce large diameter holes efficiently and quickly with less energy, faster penetration and less thrust.  Rather than drilling out the metal with a solid drill, Drillco cutters remove only the periphery of the hole, ejecting a slug at the end of the cut. 

Manufacturer: DrillCo Cutting Tools

For More Information on the Annular Cutter Sets/Fractional/Cobalt/, [Click Here] to Link to Manufacturer Web Site