Jerry is right about it being the best tapping fluid for steel and stainless steel!
But not on aluminum, it will gum up the tap and you will break the tap.
Don't ask me how I know.

Don


1967 GMC 9500 Fire Ladder Truck
"The Flag Pole"
In the Stovebolt Gallery
1946 2-Ton grain truck
1946 3/4-ton pickup,
1953 1-ton pickup
1957 1-ton flatbed dually,
1954 Pontiac Straight Eight
Of all the things I've lost in my life, I miss my mind the most!