Jeff wrote:
I need to remove an aluminum knob from a radio, but the Allen setscrew
is stuck solid.

Go to your local auto parts store and get a reverse screw drill bit.
Drill the thing out... it will probably come out from the action of
the bit long before you get drilling toward the shaft.

-- WD-40

I don't know what makes people think WD-40 acts as a penetrating oil.
It's not one. Kroil and PB Blaster are penetrating oils and they can
sometimes work although they are not as effective on steel/aluminum
sticking as steel/steel.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."