Standard covering centerline usage without a dimension 3

[Stick369]

Morning everyone. I'm having difficulty finding a standard the supports the use of centerlines when NOT used for a dimension. Recently the use of centerlines in a side view was challenged, not because it made the drawing unclear but because the individual didn't want to add them and is requesting a standard that say they have to be there. Personal opinions must give way to official standards. If there is no official standard then the company standard is applied, and changed based on the loudest voice.

Our company has required them on prints for years because it was common knowledge to use centerlines when drafting a part. Everyone does agree that centerlines are required when used to dimension a feature. But I cannot find any standard that specifies the requirement for them when used without a dimension.

ASME 14.100, 14.2, 14.24, and 14.3 all cover engineering drawings in some way and speak to the use of centerlines with dimensions. One of them talks about ensuring the drawing is clear and readable. Which lends it to the “how we apply it” argument.

ASME y14.2-20014
Section 4.7 Center lines
[highlight #FCE94F]When used[/highlight], center lines represent axes, center points, or center planes of symmetrical parts and features, bolt
circles, and paths of motion…

"When used" does not equal "must use". But in almost every example drawing used, in almost every ASME standard, centerlines are shown in side views and they are not use for a dimension. Is it safe to say that if the example drawings in the standards use them, then its a requirement? or is it just an example of "when used" but not required?

ASME y14.24-2000 fig 5.4-1

 

[3DDave]

What is not minor is there is a stubborn employee that you work with or possibly are. Why would I go to HR when it's entirely your problem? I think I see a problem of blaming others for failing to deal with an interpersonal problem.

I've worked for people who wanted dumb things and, since it did not cost the company or me to accommodate it or cause further problems with others in the company I went along with it. Likewise when there were bad effects I would ask the people likely to be affected what they preferred to do rather than heading off into legalese-ville and make others do the work.

However when poor work was rewarded by accepting it, it soon spread to other areas and other people. I watched entire departments slip to shoddy work that resulted in expensive failures from little starts like balking at putting a centerline where it clarified the view.

Yeah, a side view of a transmission plate should not have 2000 axes on it. But it should have the ones for bolt holes. In all things, moderation.

 

[mfgenggear]

exactly how ever the video I posted he talks about when it would behoove the designer when to apply center line the op post are good examples, we are talking apples and oranges here, in my day when I worked on installations of aircraft or rockets, all one got was a print with a lot of holes. or hash marks & rivet call out, but that was old school, the edge distance hole spaces were controlled by a master Mylar. now it's all cnc.

 

[mfgenggear]

the designer has to decide when for clarity, as explained in the video, it is needed to prevent confusion.

 

[Stick369]

Everyone thank you for your input. While I won't be taking one of our senior engineers to HR for out processing. The end result is that there is no requirement to have centerlines unless being used to define a feature. And if the feature is already defined in another view the center mark/line can be omitted.

Edit: typo

 

[drawoh]

Nhaner,

If you need to show roundness or symmetry, or you need to line to dimension from, leave the centreline in. If the centreline is not needed and you need to de[‑]clutter the drawing, remove it. This leaves a fuzzy area where you can be flexible.

--
JHG

 

[3DDave]

I forgot the most obvious answer - have someone else do his drawings so he doesn't have to. Essentially like the drafting groups used to do. Let those with the skills do the work they are skilled at doing. Dr's don't do blood draws and key engineers should not be sidetracked with drafting details.