GD&T
GD&T
(OP)
A few years ago I came across an Excel spreadsheet that you can take two parts and type in the dim's with tolerances using position, runout, etc. It gave you a tolerance number to use. I can no longer find it. Has anyone seen it or has anyone created one on your own? If so, can I get a copy? I am going to attempt to create a spreadsheet that is linked to design tables of parts for users to do GD&T. Thank you
ctopher
ctopher






RE: GD&T
Are you talking about the ISO tolerance letters?
Numerical tolerances are based on your application, not just the dimensions.
JHG
RE: GD&T
RE: GD&T
I am not sure of what you mean by a tolerance number. Are you talking about the actual tolerance value?
JHG
RE: GD&T
RE: GD&T
Your tolerances are based on your requirements. For positional tolerances for screws through holes they are
Floating: holeMMC - screwMMC
Fixed: (holeMMC - screwMMC)/2
For everything else, you need to know what kind of fit you want. The ANSI standard fits in the Machinery's Handbook are a good start. There is a page showing what manufacturing process achieve the fits. You do not want to weld to +/-.0001" if you can help it. :)
JHG
RE: GD&T