Ever since the weenies took the good stuff off the market (111 trichloroethane) I have used Tap Magic as a tapping fluid.
I'm tapping a 20mm x 2.5mm hole in 1018 cold roll, about 20 pcs. It is an old wore out tap that I didn't want to replace because I'm not getting that much for the job. I'm using my Carlton Radial and was getting down about three threads before the tap started spining in the chuck.
A saleman had dropped off a sample of Castrol Moly Dee for me to try about 6 months ago. The tap is now blowing thru 2" of material.
It takes a lot to impress me. I'm impressed.

you castor oiled moly dee - i bet she wasn't to happy about that (hey its friday and been a long week)

Good stuff but I can never get the smell off my hands.

I've found that Castrol Moly Dee is about the only lube worth a flip when trying to run taps through stainless by hand.

I keep a bottle of it around myself, and realy like it. The other that I use more often, is much cheaper, and nearly as good is Re-Li-On.

I lucked out yesterday.
I had a MSC flyer that had Moly Dee on sale. Normal price is $168.21 a gallon. Sale price was $99.99 a gallon. Bought 5 gallons. Ought to last a while.