>
>
>Hi,
>
>I'd like to cut some circular holes in sheetmetal for gauges.
>
>Does anyone know how to create these kind of holes?  I know how to do it for
>wood, but I'm not sure this would work for metal.
>
>Any help would be appreciated.
>
>..Markus
>
>----------------------------------

   The subject hasn't really been covered too well as far as I know
  but there are two relatively easy ways if you have a flat surface.
   The do have Hole Saws up to about four inches just like for wood.
  The good ones aren't cheap and the cheap ones will eat your arm off
  if you aren't careful. Now that I think on it so will the good ones.
  
   More appropriate is what's called a "Chassis Punch" used in elect-
  ronics and electrical industry. The small ones that most of us have
  seen are a screw type chingadero that just needs a pilot hole.
   
   The bigger ones(up to 6") are a portable hydraulic rig. Like a 
  "Porta Power" set-up. This called the Greenlee Chassis punch set.
   
    The "How to": In my small town I jam down to the local sheet-metal
  fabricating house, he has a set. They or I drill a 3/8" hole in the
  center of my hole then put in the proper size punch an pump it up.
   About thirty seconds and I've got the perfect guage hole.
  
   An alternate source is just about any electrical contractor.
  They use them to punch holes in the electrical boxes for wiring 
  access. They call them "knock-out punches".
  
   Looking in my '89 Mcmaster-Carr catalog it lists a set with 1/2"
  thru 4" for $805 . A little pricey to be buying for a couple holes.
  
   My sheet metal shop charges me ten bucks and that's just to keep
  me from becoming a pet.                 west