Xcelte is the brand to count on when needing to place high torque on stubborn set screws (also called grub screws) used on vintage radios and other electronic equipment that has knobs attached to shafts with....you got it....set screws, both hex and Bristol.On one job with particularly difficult set screws (twelve knobs to remove from a WW II radio and every dang set screw - 1/16" hex 6 X 32 thread - was frozen solid! After a first pass on each set screw with no joy, I used my favorite penetrant, PB Blaster, kept the set screw wet for 24 hours, and went after it again with the Xcelite "blade" and handle.(For the record, I have used MANY different Allen wrenches, including Craftsman, Harbor Freight, etc., and also have broken, twisted, rounded off ends, on less demanding jobs that I am describing.. anyway, I digress...)The Xcelite blade withstood almost a 180 degree rotation time after time without complaining. (Other brands would have snapped off or rounded off ) This allows for a LOT of torque. Some set screws required three rounds (72 hours). There is no way this job would have been accomplished without this tool! Thank you Xcelite!!