I just received this from a friend and thought you may find it useful:

Some of you might appreciate this. Machinist’s Workshop magazine tested penetrants for break out torque on rusted nuts.

They are below, as forwarded by an ex-student and professional machinist, Bud Baker.

They arranged a subjective test of all the popular penetrants with the control being the torque required to remove the nut from a “scientifically rusted” environment.

*Penetrating oil ….. Average load*
None …………………. 516 pounds
WD-40 ………………. 238 pounds
PB Blaster …………… 214 pounds
Liquid Wrench ……… 127 pounds
Kano Kroil ………….. 106 pounds
ATF-Acetone mix…….53 pounds

The ATF-Acetone mix was a “home brew” mix of 50 – 50 automatic transmission fluid and acetone. Note the “home brew” was better than any commercial product in this one particular test. Our local machinist group mixed up a batch and we all now use it with equally good results. Note also that “Liquid Wrench” is about as good as “Kroil” for about 20% of the price.