How many amps for different thickness HR?

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I just got a PT 185, is there a chart for amps required for different thickness Hot Rolled?
Reply:Howdy!  the most general rule of thumb is 1 amp for every thousandths of material (steel).  ROUGHLY...  Now with the newer waveform technology i.e. pulsed waves and such, it can cut that amperage way down.  SO... 185 would be good for .185" thick steel...or so.  Now with my old technology 90-105 amp cheepy century mig, I can weld 1/8" beautifully, 3/16ths satisfactorily, and 1/4 inch, ugly with alot of weaving, and probably not to 100% structural strength.  ... hmm nead a longer reply. brb.  Brian Lee  Sparkeee24
Reply:Howdy again!  OK... at 185 amps, your only looking at a 15% duty cycle...but anyway.  SO  My chart  from a miller book)  says 1/4" butt joint 1/8" electrode, 5/32" filler rod, 160-175 amps.  1/4" lap joints same with 170-200 amps, 1/4" corner joints 160-175 amps, fillet joints 175-210 amps. all with 100% argon, at 20 cfh. again, all with 1/8th" electrode, 2% thoriated.  I believe the method of creating the steel has more to do with heat treating if tempered, and grain characteristics, and less with required heat input to fuse a joint.  It says the tungsten should be pointed or tapered to a slight flat.  It says hot rolled has mill scale that must be removed first.  I too have found that to be true with my crappy mig welder.  At first few welds, you'll think it's all clean just cause it's bright and shiny.  But then if your at it for another minute, the "scale" starts flaking off, and a bright steelhead shiny steel shows through!  I'd say it's about as thick as a sunburn peeling   I would fiddle with the pulse setting too, I have HEARD that it can make the weld seem as if you have 20% more heat input for thicker welds, and/or better control at lower setting on thin sheet metal ot alluminum.  Well, all this is book stuff, just got my first tig torch today, and I don't even have a machine for it yet!!  Happy Welding!  Brian Lee  Sparkeee24