Quotation of drawings


#1

From the French rules this drawing is overquoted, meaning it is not made under the rules of the Art.

We have a first dimension
"Thickness of the cylindric part of the rim" = 1.05 - 0.15
a second dimension
"Total thickness of the rim" = 1.65 - 0.15

Therefore we don’t need the "difference" = 0.60 (which furthermore given with no tolerance, this being an error)

  1. I would like to know if NOWADAYS in the other countries (England, Germany, USA) it is the same (unnecessary over quotation, furthermore incorrect because the lack of tolerance)

  2. Perhaps this drawing is correct because either it is not made under french rules or perhaps because the rules changed during the years.

This drawing is German and dated from 1920.
Perhaps the rules of this old time mean we must keep a constant difference between the two dimensions (due for example to the manufacturing process)

What do you think ?
thanks
JP


#2

I do not see the error. Drawing is correct. The thickness of the rim can be made ​​in the size range of 0,45-0,75 mm. Why do you think that the rim thickness constant?


#3

Hello 2moutrage,

  1. I agree with you:
    From the min and max dimensions we can deduct the flange thickness can go
    from 1.50 - 1.05 = 0.45
    to 1.65 - 0.90 = 0.75
    (and giving of course an average of 0.60)

The question was : why to write 0.60, which is unnecessary and furthermore not correct (at least in france)?
Is it correct in your country ??

  1. my guess was : perhaps in the old time in germany this had a special meaning :
    keep constant this dimension, meaning the cylindric part and the total thickness are corelated
    or any other meaning.

  2. If somebody shows me a drawing quoted like that I would at once tell him to go back to school to learn his job better.

But when you know this drawing is coming from a german factory (german people are very very serious) and furthermore from RWS, I am not 100% sure the guy mistook !

It is for that I am looking if there is not a special reason (about which I don’t know) to quote a drawing in such a way
JP