Head Mount Milling Machine Guard It installs quickly; no drilling is necessary because it is truly bolt-on. Use the longer bolts that are provided to bolt to the quill feed selector. It fits a variety of manual vertical milling machines, including those made by Bridgeport, Sharp, Jet, Trak, Prototroch DPM, HH Roberts, Causing, Laguna, Webb, Supermax, and Alliant. For simple setup and work availability, the front arm swings open to the left by 180 degrees.