twe56 Depends on what size hole and the material you are drilling. Most people make the mistake of running the drill RPM too fast. As a general rule the bigger the diameter the slower the speed. Also a HSS bit will drill almost any steel if the feed and speed is correct. A slow speed with lots of pressure works best on just about any type of steel except anything that has been heat treated. You can use cobalt or carbide bits but if you run them too fast the corners will come off and the bits will be useless. I use the heavy thread cutting oil that the plumbers use as a lubricant. Try lower RPM and more pressure. Weeds

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