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ISO Drawing unit

ISO Drawing unit

ISO Drawing unit

(OP)
A question arised in my group..
Where is it stated that the units in an ISO drawing are "mm"? In which standard?

I'll be very happy to find this info smile


-RR

RE: ISO Drawing unit

ISO 129-1

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

RE: ISO Drawing unit

(OP)
Can't find that "mm" is mentioned, but if you mean chapter 4.1 - last section?

"Where all linear dimensions are expressed in the same unit, the unit symbol may be omitted, provided the
drawing or associated documentation carries a statement of the unit used."


By this I read that it should be stated in the drawing that all dimensions are in "mm". No standard is telling the default unit for an ISO drawing.
Agree?

-RR

RE: ISO Drawing unit

I mean Chapter 4.3 Units of dimensions referencing SI units.

Which year is your version of 129-1?

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

RE: ISO Drawing unit

(OP)
Ok, but still chapter 4.3 only state SI units, not "mm" in specific.
I know that the relevant basic SI unit is "m", but with the allowable prefix(es) there can be "cm", "km" and "mm" :)

My version of 129-1 is from 2004. I see that it is foreseen a new version this year.

-RR

RE: ISO Drawing unit

rumlyronny,

I have a copy of ISO 406 Technical Drawings -- Tolerancing of linear and angular dimensions. Under Units, it states that "Deviations shall be expressed in the same unit as the basic size." As per ISO 406, you can dimension in furlongs if you want, but you have to express tolerances in them too. I assume you need a note on your drawing indicating what the dimension units are.

--
JHG

RE: ISO Drawing unit

(OP)
Thank you for your time :)
I'm quiet happy smilethumbsup2

-RR

RE: ISO Drawing unit

So am I.
ISO 406 is happily discontinued. Perhaps for mentioning furlongs smile
There is a small hope that ISO 129-2 could shed some light on the issue, but unfortunately it still in Draft stage since 2013

"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future

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