Manual says to use drill bits as gauge but numbers?

cannucky said
Well around here none of the industrial supply house's like Granger or National Concrete stock them , they will of course order them in but that's a different story now isn't ? The same can be said for Homo Depot , Lowes , Cambodian Tire and all the local Lumber Yards which takes care of all the "Tool Stores" in this city .
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I see you are not in the U.S. Things are different here, I guess. I could find those drills at any True Value or Ace hardware store. Tool stores like MSC, and even Harbor Freight have them. I'm quite sure well-stocked NAPA stores have them too. And then there is Sears.