Londonderry,
The flatness or straightness call-out depends on the amount or warpage you are can allow and the material thickness tolerance. Remember rule #1 (perfect form at MMC). If the plate spec is .25±.01 thick, when the part is produced at .26, it must be perfectly flat. When the part is...
cadfreak,
The specification of the material on the drawing should fully define the requirements necessary for the design. For instance: 304L is more suitable for welding than 304. Thus, unless you are not welding or the low carbon requirement of 304L is not required, you may call out the two...
Hello everyone,
I have the following situation and I would appreciate if someone can suggest a tolerancing scheme for the following group of holes: I have three holes. The circular outside boundary of the part is not important. The three holes are inline. The top and bottom holes have a tight...
Paul,
Thank you for correcting my mistake. As Paul correctly stated "When the callout is applied to the feature of size dimension however, it is not directionally dependent as it constrains the derived axis or derived median plane within a cylindrical or parallel planes zone, therefore it is...
jec3300,
What you describe doing with the U-shaped fixture is no-go gage for straigthness of a feature of size (FOS) at MMC.
The Flatness of a FOS surface cannot exceed its size tolerance. Rule #1 (perfect form at MMC) prevents this from happening. For instance, if the a bar is .25±.01 thick...
So what happend to "The common element on all 4 cases in 2.3.2 is that the tolerance has the same number of figures as the dimension"?
Let's review:
We agree that the size dimension and tolerance should have the same number of decimal places: 3125 +.0000/-.0030 (para 2.3.2(b) of ASME...
What happens if we change the problem a little bit. Let's say the feature is the primary machining feature in a casting where the location of the feature is not too important. This primary machining feature is located from datum targets using basic dimensions. So we have the following:
Hole...
EWH, thank you very much for your responce. Unfortunately, I think the reason you gave does not apply in this case. Paragraph 2.3.2(d) of ASME Y14.5M-1994 applies to toleraces associated with a basic dimensions. In my example, the feature is a cylinder and it is the primary datum feature.
I would like to know what your opinion is regarding the number of decimal places of form tolerances. ASME Y14.5 says that inch dimensions and their tolerances should have the same number of decimal places e.g. .500±.125 or .3125±.0010. Now, if we add a form tolerance, say circularity. Should the...
