I'm sure there are some knowledgeable machining and tool guys here, what's your favorite tapping fluid?
Recently when I was drilling a rotor, I ran out of one cutting oil, changed to another bottle
(of

) and instantly stopped cutting. I wrecked a couple drill points and work hardened 3 holes. I had to pre-drill the centers with a masonry bit and finish them with some difficulty.
The Millwright/Carpenters I used to work with liked Tap Magic, but I haven't had any for a while. Before I buy a can, is there something better for hand tapping or drill press use?
I bought some blue gel stuff at Lowes but wasn't impressed.