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Something I would like to pass on. I had to drill some 2" holes thru the winch mount push bar assy on my Crawler/Jeep/Truck/thingy and nearly took my arm off when the drill bit mounted in the hole saw broke. Not smart enough to evaluate the cause I replaced the drill bit and broke another within seconds. It is important that the locating piece of the hole saw be round smooth material, the shank of the drill or as I do now a smooth mandrel, not the flutes of a drill bit. The flutes will catch then bind and break leaving the hole saw running amuck.

Always predrill the center hole when cutting metal. on softer materials it isn't always necsessary.

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Mechanically able, Monitarilly challenged

Yep.. I've had similar close calls doing suspension work on rock crawler projects. I have a 3/4 horsepower Milwaukee gear reduction 1/2" drill that came real close to breaking my arm a couple times when the bit got jammed in the hole. Lucklily it snapped the 3/4" bit in the process. I now use a 2-3 ft cheater handle (some black iron pipe) attached to the drill to prevent it from getting away from me.

For big holes, i use the plasma cutter anymore. I hate hole saws with a passion.

Drilling the pilot hole wasn't the problem rather durring the actual cutting the flutes fo the drill caught breaking the drill. I have since drilled the pilot hole then substituted a mandrel for cutting the hole with no problems.

I had a hole saw bit mounted into my drill press. I was drilling a fairly big peice of sheet metal and the bit cought the sheet and swung it like a big sword untill it slammed into the press. It also planted about 4 inches of sheet metal in the drywall of my garage. Thank god I wasn't between it and the press.