It increases the "bite" of the screwdriver tip in the screw head, helping prevent it from ramping out.Glenardo wrote:Why valve grinding paste??? That's a new one for me!!
My secret tip is Type "F" auto tranny fluid. The best rusty bolt remover I had ever found. An old alignment shop (not computerized) guy told me about it years ago and it works great. I have some in a oil squirt can that I squirt a little bit on any rusted bolt/nut before removing.
Some screwdrivers also have raised ribs on the vanes for the same purpose.