Allowences And Tolerances

[uncle harry]

I'll grant that the method of expressing the dimensions in the fit chart is a little awkward. It does not follow normal machining "lingo", but the information is clearly expressed and accurate. I've been at this a while, and to me it makes perfect sense. However, if I needed to use this type of information on a regular basis, or had employees who used it, I would probably "translate" this chart into something more people are accustomed to seeing.

My training for specifying tolerances or fit on drawings has been to use limit dimensions following a specified "target" dimension. These are shown as a fraction with a plus sign on the numerator & a minus sign on the denominator for a hole and the reverse for a rod or shaft. This gives a range of acceptable finished sizes between components. My Autocad Inventor Light provides for this as well as alternate methods to specify fit dimensions.

 

[Swerdk]

So let me see if i got this right?
0.2 is read as .0002
2.0 is read as .002
.25 is read as .00025
.020 is read as .00002

If i am right then i am starting with .000 and adding the number listed behind it. Do i get it?

Sad part is i kinda wanna know what is basic allowance between two sliding parts.

 

[Tony Wells]

I believe you have it.

There is no real straight up answer to that question. It depends.....on things. If you give a specific example, I'm sure we could work out an answer.

 

[Swerdk]

Its a start for now


Sent from my iPhone using Tapatalk

 

[Bill Gruby]

As I see it yes, you have it correct.

"Billy G"