Many of our gunsmith customers have told us this is the best product we've ever offered for tapping, drilling and cutting all types of heat-treated steels, moly and stainless. Excellent for chambering and boring jobs, a coolant for lathe, mill and shaper work will speed production and reduce tool costs in your shop every day. Non-evaporating, does not require stream application for 99% of the jobs, it follows the tap or drill in the work. A moneysaver. We know of cases where all four holes for a mount have been drilled and tapped using DO-DRILL"!, and the tap was still sharp enough for future use. With taps as high priced as they presently are, you cannot afford NOT to use it.