From: null@void.com   
      
   Hi all   
      
   Working with   
   Rectangular Hollow Sections   
   Square Hollow Sections   
   box sections   
   ...   
      
   The rounded corners make using an adjustable square / sliding square   
   problematic.   
      
   Given number of machine parts I have to make quite accurately based on   
   SHS's, thinking of a tool specially optimised for marking distances   
   from the surfaces.   
   ie. whatever presents as "top", slide along marking down the "sides".   
   Typically the middle of the "sides".   
      
   Accuracy - well using a chalk / soapstone is plenty good enough.   
   Have to bring magnetic-base drill to the job most of the time, and   
   with using a shell-cutter / trepanning cutter with a central "pin" to   
   locate on the centre-pop - accuracy there is less than chalking gives.   
   So - would hold thing in place and chalk-mark.   
      
   I could trim offcuts of angle-iron to make single-dimension tools -   
   eg. marks 25mm from "top" surface.   
   Advantage with this or "settable" tool is spin around 180deg and mark   
   the other "side" and the two heights/levels should match-up.   
      
   Hope described this well enough.   
      
   Best wishes   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)