Metric Call Out on a print (from Japan) - 40mm +.002/+.015

[Michael_M]

We got a metric print (from Japan). Is it common for a dimension to be called out as a positive/positive or negative/negative tolerance?

For example 40mm +.002/+.015.

the way I interpret this, the dimension would be 40.002/40.015 (say for a bearing press fit).

We have the question submitted to our customer but have not gotten anything back yet so I thought I would ask here.

[David DeLong]

Yes, I agree with your interpretation 40.002 - 40.015

[Stijloor]

In Reply to Parent Post by Michael_M

We got a metric print (from Japan). Is it common for a dimension to be called out as a positive/positive or negative/negative tolerance?

For example 40mm +.002/+.015.

the way I interpret this, the dimension would be 40.002/40.015 (say for a bearing press fit).

We have the question submitted to our customer but have not gotten anything back yet so I thought I would ask here.

In the ISO System of Limits and Fits, the tolerance zone can shift above and below relative to the nominal dimension. This way, the engineer can design any type of fit for two mating parts. Look at par. 1.6 for an interpretation.

Stijloor.

[Miner]

I have previously worked at a company that was a joint venture with a Japanese company, and we supplied product to Mazda. This scenario was relatively common for mating dimensions.

[Danny Hoover]

40.002 - 40.015 is correct. What inspection method would you use to verify a tolerance range so small?
Danny

[bobdoering]

In Reply to Parent Post by Danny Hoover

40.002 - 40.015 is correct. What inspection method would you use to verify a tolerance range so small?

That depends a whole lot on what kind of feature it is. Air gage, indicator, laser - there are a variety of options. It also depends on if it is a feature you wish to control or just verify as meeting specification.

[AndyN]

In Reply to Parent Post by Stijloor

In the ISO System of Limits and Fits, the tolerance zone can shift above and below relative to the nominal dimension. This way, the engineer can design any type of fit for two mating parts. Look at par. 1.6 for an interpretation.

Stijloor.

Jan - I was thinking it was familiar - not a Japanese tolerancing technique, just an option under the ISO system.

[Stijloor]

In Reply to Parent Post by AndyN

Jan - I was thinking it was familiar - not a Japanese tolerancing technique, just an option under the ISO system.

Nope, not exclusive Japanese..

ISO 286 (part 1 and 2) Standards are very common outside of the USA.
(ISO 286 was part of my Machinist Apprenticeship training curriculum.)
Here in the USA, they're almost not used...
Hence the confusion..

See: ISO 286-2:2010 and ISO 286-1:2010

Stijloor.