SI units tol 5

[ctopher]

How do you read these tolerances?
Not sure how to add this symbol here, but "<_" is "less than or equal to".

x<_10, +/-0.1
10<x<_100, +/-0.15
100<x<_500, +/-0.25
500<x, +/-0.5

If a dimension is 165 or 22.5, what tolerance is used?

I have never used this type before.
Thanks.

Chris
SolidWorks 10 SP5.0
ctopher's home
SolidWorks Legion

 

[ctopher]

I understand math, but I'm used to having each decimal place using a different tolerance.
Example:
.X = +/- .02
.XX = +/- .01
.XXX = +/- .005

This is not the same as the below if the decimal places in the tol block are different, only if they are as the ISO stated previously.
10.2 +/-0.15
10.425 +/-0.15

It's just as simple as I'm not used to using ISO.

Chris
SolidWorks 11
ctopher's home
SolidWorks Legion

 

[fsincox]

I was not easy for me either and for reasons I have given before I got to like it as, well, basically a less simplified general tolerancing method than the way we do it. I have yet to really have a dialog with people who use it seriously, kind of like GD&T most only seem to pay lip service to it, IMHO.
Frank

 

[looslib]

ISO 2768 by itself is NOT a valid identifier on the face of a drawing for the tolerancing standard. ISO 2768 must include the tolerance class, f(fine), m(medium), c(course), or v(very course).

From table 1 of ISO 2768-1, a dimensions of 25mm would have the following tolerances based on tolerance class.

f 24.9-25.1
m 24.8-25.2
c 24.5-25.5
v 24-26





"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli

 

[pmarc]

Please let's not mix ISO 2768 with the ctopher's example being discussed. Nothing on the print says that this standard should be used for any tolerance interpretation. The general tolerances chart is only a convention. Someone picked a method that seems to be based on a 'manufacturing method accuracy vs. feture dimension value' concept - which is obviously more common in ISO world - but the numbers do not have to be corelated to ISO 2768 and the method itself is not reserved for tolerancing according to ISO.