I have used my Oneway Stronghold chuck for many years. I am always careful not to overtighten the hex screws when changing jaws. This week one of the screws would not come out. I doused it with WD 40 but partially stripped the hex head so that the supplied hex driver wouldn't work. Fortunately I had another 4mm T handled driver (thank you Harbor Freight!) which fit adequately. More WD 40, left it overnight. Tapped it with a punch and hammer, tried tightening and reverse tightening. Frozen! Bought PB blaster and soaked it several times. Nothing. Soaked it again and left it for 2 or 3 hours. And then it loosened! This may be old hat to those of you shade tree mechanics out there but I learned these lessons: 1) be more vigilant about tightening the screws in the future when securing chuck jaws; 2) PB blaster (I was very aware of the product but had never used it) is probably superior to WD 40 (which I have always used) for this sort of frozen screw/bolt situation; 3) patience is a virtue in this situation; 4) periodically examine the machine screws and discard any with 'rounding' of the hex recess just in case. Nothing very profound in all of this but I was so happy to have my chuck back as I needed it!