These arbors are designed to adapt conventional machines eg. drill presses lathes milling machines and others to accept Holemaker annular cutters. This becomes a very economical alternative to normal methods of drilling or boring large diameter or deep holes. By adding an extension arbor and long series annular cutter to your industrial arbor you can achieve depths of up to 320mm in hollow section steel. Time savings in excess of 40% over normal drilling methods are not unusual. Specifications Morse Taper: #4 MT Maximum Depth of Cut: 110mm To Suit Shank Size: 3/4