"B.B." u wrote in message
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In one of my classes we're reflooring a trailer. Lucky me I get to
drill all the holes. #16 drill bit. 2" boards on top of steel frame
members about 1/8" thick. I'll drill the wood, clear the chips, then go
through and dill the frame. So far I've been sticking with relatively
low speed and high pressure. Is that the best way to do it, or should I
trade off for more speed/less pressure? A HSS bit will go about 40-50
holes before getting uselessly dull, but occasionally I'll strike a weld
over and old hole and that'll significantly shorten the drill's life
span.
Is 40-50 holes expected? Anything I can do about the welds short of
dumb luck?


My drilling technique is this:

I watch the cuttings. I NEVER use high speed. As long as I can see
cuttings, I just keep up the pressure. Most of my drilling is at medium
speed or less. I think that when I am cutting at my best speed/pressure
combination, I see spiral cuttings.

Works for me, anyway.

Steve