i usually soak them in kroil or something like that at least overnight.
Make sure you have the right type and size turn screw, try tapping before hand to try and loosen it a bit.
Lastly if you have no luck soaking it and re soaking and trying to loosen it by hand, try using a drill press to hold the bit in the slot very tightly.
Obviously you are NOT turning the machine on , just using the pressure to hold in the bit, then try moving your chuck just ever so lightly.
be very careful to keep constant pressure until the screw breaks free, then release the pressure as it moves.

if you can get heat on that screw it usually will allow the crud underneath to loosen, good luck.

Last edited by tigertrout; 12/25/24 11:14 AM.