My black smiths’ wall drill has a Jacobs 34 (1/2″) chuck,the chuck has a 1/2″ dia shaft with a Jacobs taper into the chuck,the 1/2″ piece goes up the mandril,and is retained with a grub screw.The black smiths drills have a 1/2″ shank.I got sick of cranking so I fitted a 1/4hp motor,and run the drill at 120 rpm.The machine has a simple auto-feed system.You should have no problem getting blacksmith drills,we can get them here in NZ either carbon or HSS,either singels or boxed sets.Ian S C