Sorry no pictures with this one,

When you want to use a large drill (1inch or bigger) in thin sheet metal, if you are not careful you will or may produce for better words, a square hole, just take an old or new piece of cloth or rag big enough to be able to fold it over two times then place it under the drill bit (with a pilot hole first drilled) and you should end up with a nice round hole, 

Of course before you start make sure you have glasses on and the sheet is clamped in some way and be careful, think safety,

…………Edmund……….

Alexander m,

    I' not going to get into an argument with you, you use wood, I use cloth,

Edmund,

GarethBell

That's fine by me, its not written in gold, whichever works best for you, I have always used a small piece of rag you use wood, there are many ways to skin a cat,  

……….Edmund…………

GarethBell,

      I have only used this op a few times, I'm familiar with most if not all the ways to produce a large hole in fact I have two home made tree panning tools, but I was shown this cloth thing by an old experienced toolmaker, and it works, I cut or tear any old kind of material big enough that when its folded in half twice, I've never tried 3 or 4 times I don't think it would matter how many times, as long as it is just a bit bigger than the drill dia being used, I think the principle of the whole thing is that the rag is drawn into the hole being produced and taking up space between the flutes but that is just my theory,

Alexander m, there shouldn't be any great chunks of cloth flying around, just a little bit bigger than the drill, I guess I could have explained better in my first post, that seems to be a common occurrence these days, myself included, sorry about that,

………..Edmund………