[TheForge] slitting and drifting help needed

[Demon Buddha]

robert hensarling wrote:
> Guys, is there a reference, or chart maybe, of what size slitting 
 > chisel to use for a given drifted hole diameter?  In other words, if
 > I want a drifted finished hole size to be 1/2", what size of slitting
 > chisel would I use, not only for this size, but 3/16th's, 1/4, 3/8th's
	
	Your sizes seem a bit smallish here.  I see no reason to slit a 3/16" 
hole.  Either punch or drill.  At any rate, for a given chisel width, 
the minimal circle diameter it will accomodate is about 60%.  So a 1" 
chisel will be good for about 5/8" round hole.  You can drift further if 
you want, but if it's much more than that, you should probably use a 
broader chisel unless very thin "walls" are not a concern.  Square holes 
fit to similar proportions.  Also realize that these are approximations 
because ever chisel is a little differently proportioned.