09-27-2012, 08:10 PM
Don't have a set. They're supposed to be for removing broken bolts I think, the idea being if they grab it will back the bolt out. Can't imagine them functioning very often, if the bolt broke its usually rusted in or over torqued, in either case it takes a fair bit of torque to remove the bolt, more than I can see the drilling action giving.
Free advice is worth exactly what you payed for it.
Greg
Greg