Had to drill an 1-1/18" hole into four, 1/16" thick, aluminum plates First hole was fine. Second Plate hole to be drilled became difficult at the 1" Step and couldn't get to the 1-1/8" step. Third and fourth plate holes to be drilled almost reached the 1" Step, but again, not to the 1-1/8" Step I needed. I used a Drill press, at a slow, steady pressure, to no use. No directions included. Didn't think of using "coolant". Didn't read ALL the reviews to find this out from other buyers. Really didn't think I had to turn my workshop into a machine shop and have "coolant" or cutting oil(?) dousing the step drill to drill 1/16" aluminum plate. Really?