Break Free
is the best and most reliable for loosening anything frozen up. It does not thicken with low temperature, and does not dry to a thick mass when aged. It is the best for gun parts and general lube uses. It is also probably the best kept secret in lube stuff. Wd 40, and most of the others, cannot hold a candle to Break Free. No, I don't sell it, but I buy lots! Really great stuff, try it.
Ron