Position of the diameter symbol

[sibannister]

This is only a pedantic query, but it will solve an on-going debate at work - namely, where should the diameter symbol (%%C) go? Before or after the number?

I feel it should go before the number, but my colleagues all say otherwise, even though AutoCAD automatically puts it before the number when you do a Diameter Dimension.

%%c100mm -or- 100mm%%c?????

Cheers in advance for any help,

Simon.

[Anonymous]

My answer to this has always been: How would you read it in a book? As Diameter 3" or 3" diameter? I am not a fan of autocad's automatic entry of diameter or radius BEFORE the numerical entry. I have always advocated they be AFTER the numerical entry. I try to remind my students that a drawing is a picture of a book.

[Anonymous · Accepted solution]

Hi Si,

Old School vs. New School
100mm%%c -or- %%c100mm
after vs. before

I started drafting in Jr. High School (note before Middle School days) and we were taught "after". I always practiced after all thruout my "Manual Drafting" days. As well as when I started CAD in 1986.

But by the time we started AutoCAD, we also started to adhere to "ANSI STANDARDS" currently ASME Y14.5.1M-1994, which is on our TitleBlocks.. We MUST practice the New School or we are out the door.

At first I didn't like it as old habits are hard to change. And I still don't agree with all of the STANDARDS, but who does????

So I say to you and everybody %%c FIRST. (diameter 1st)
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Reply From: Walt Engle
Date: Feb/24/05 - 11:05 (CST) NEW!

Re: Position of the diameter symbol
My answer to this has always been: How would you read it in a book? As Diameter 3" or 3" diameter? I am not a fan of autocad's automatic entry of diameter or radius BEFORE
the numerical entry. I have always advocated they be AFTER the numerical entry. I try to remind my students that a drawing is a picture of a book.
*****************************
Hi Walt! I say to you...how do you read 3 dollars as 3.00$ or $3.00? It's all a matter of getting used to something.

And you say you "TEACH"??? 21st Century is here already Walt. If you are going to teach, at least teach what's correct. Here's a little test for your students;

Which is correct and why?

%%c0.025 or %%c0.025" or %%c0.025mm or
%%c.025 or %%c.025" or %%c.025mm

[Anonymous]

Per ASME Y14.5M-1994. -- Robert Davis QC/CMM Dept. [email protected] E.A.S. Manufacturing Co., Inc. 804 Via Alondra Camarillo, Ca 93012 805-987-3665 Voice 805-987-7948 Fax [email protected] - General E-Mail www.easmfg.com - Web Site "SiBannister" wrote in message news:[email protected]... > This is only a pedantic query, but it will solve an on-going debate at work - namely, where should the diameter symbol (%%C) go? Before or after the number? > > I feel it should go before the number, but my colleagues all say otherwise, even though AutoCAD automatically puts it before the number when you do a Diameter Dimension. > > %%c100mm -or- 100mm%%c????? > > Cheers in advance for any help, > > Simon.

[Anonymous · Accepted solution]

Hi Simon, There is no need for argument at all. Point your colleagues to the drafting standard which is used in your country and it will be the end of all drafting arguments. Regards, Igor. -- To reply please use [email protected] address SiBannister wrote: > This is only a pedantic query, but it will solve an on-going debate at work - namely, where should the diameter symbol (%%C) go? Before or after the number? > > I feel it should go before the number, but my colleagues all say otherwise, even though AutoCAD automatically puts it before the number when you do a Diameter Dimension. > > %%c100mm -or- 100mm%%c????? > > Cheers in advance for any help, > > Simon.

[sibannister]

Cheers Robert for that - especially the JPEG. Should have seen the look on my colleague's face when I sent that to him!

[Anonymous]

Glad to help. :-) -- Robert Davis QC/CMM Dept. [email protected] E.A.S. Manufacturing Co., Inc. 804 Via Alondra Camarillo, Ca 93012 805-987-3665 Voice 805-987-7948 Fax [email protected] - General E-Mail www.easmfg.com - Web Site "SiBannister" wrote in message news:[email protected]... > Cheers Robert for that - especially the JPEG. Should have seen the look on my colleague's face when I sent that to him!

[Anonymous]

but if you noticed, autocad isn't going to give you that "exact" standard regardless. if you're committed to that standard, then you must edit the font to enlarge the symbol to be 1.5X the letter height. or only use mtext for it (which allows individual character heights). "Robert Davis" wrote in message news:421f6047$1_3@newsprd01... > Glad to help. :-) > > -- > Robert Davis > QC/CMM Dept. > [email protected] > > E.A.S. Manufacturing Co., Inc. > 804 Via Alondra > Camarillo, Ca 93012 > 805-987-3665 Voice > 805-987-7948 Fax > [email protected] - General E-Mail > www.easmfg.com - Web Site > > "SiBannister" wrote in message > news:[email protected]... >> Cheers Robert for that - especially the JPEG. Should have seen the look >> on > my colleague's face when I sent that to him! > >

[Anonymous]

On Thu, 24 Feb 2005 16:53:21 GMT, SiBannister wrote: >This is only a pedantic query, but it will solve an on-going debate at work - namely, where should the diameter symbol (%%C) go? Before or after the number? > >I feel it should go before the number, but my colleagues all say otherwise, even though AutoCAD automatically puts it before the number when you do a Diameter Dimension. > >%%c100mm -or- 100mm%%c????? Refer to your national technical drawing standard. The vast majority of national standards specify the symbol before the numbers.

[rileybreed]

I know it's an age old discussion, but I need to find some sort of definitive proof.

The ASME Y14.5.1M-1994 only refers to Metric dimensions. What about Imperial dimensions?

Shall all Metric have it before and all Imperial have it after? Where is a legitimate document that states this? Is there an ASME Y14.5.1Imperial?

[jggerth]

ASME standards American Society of Mechanical Engineers

• ASME Y14.41-2003 Digital Product Definition Data Practices
• ASME Y14.5 - Dimensioning and Tolerancing
• ASME Y14.5M-1994 Dimensioning and Tolerancing
• ASME Y14.5.1M-1994 Mathematical Definition of Dimensioning and Tolerancing Principles

You may want to look into GD&T documentation -- the tutorials I found showed the dia symbol in front of the number -- but did not cite a erference for that practice.  it may be in ASME Y14.5.  it's not referenced in the NCS or UDS manuals

[GrantsPirate]

The ASME Y14.5-2009 only applies if you are stating on your drawings that you are adhereing to that standard.  Paragraph '1.1.2 Units' says that while SI units are used in the Standard, Customary units could have just as well be used for illustrations.  In other words they are promoting SI and hoping the US  joins the rest of the world but the other units are valid as well.

[Anonymous]

It has been awhile since I went through drafting school, but (in mechanical drafting) the diameter symbol is a geometric designator and goes before the numerical designation which is follow by the units designation. In the same sense that the square, angle, and radius (R) symbol are used. In the old days (dia) was used rather than the diameter symbol, and it came after the units designator. I believe that the 'old school vs. new school' is perpetuated by the 'lack of drafting skills vs. strong computer skills'. In the old days of drafting, staircase direction was drawn with an arrow pointing in the rise of the stairs and never the decent, but these days, no longer. I have seen CAD techs dimension arcs with a diameter and circles with a radius. Many I have seen, are even clueless about lineweights and text height. I believe it is a simple matter of "It is easier to change the standards than it is to learn them" attitude. Just my two cents!

The longest distance between two points, is a shortcut.

[GrantsPirate]

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Many I have seen, are even clueless about lineweights and text height. I believe it is a simple matter of "It is easier to change the standards than it is to learn them" attitude.

For some reason I read that in Yoda's voice in my head.   Time to go home it must be.

[Anonymous]

"For some reason I read that in Yoda's voice in my head.   Time to go home it must be."

That's funny.......I was feeling a little shorter than normal when I wrote it.

The longest distance between two points, is a shortcut.

[Richard.Vivanco]

In my case i use this specific symbol before the number.  But for other symbols like dimensions or degrees i put after the number

[Anonymous]

Hi Si,

It doesnt look like anyone here has any on site experience as a tradesmen so from a welder/ fabricators experience making diameters in a whole variety of material we would always write ∅20mm as in, the "diameter of 20mm" is required.

Dont even try, def dont get used to doing it the wrong way by people who never used it outside of CAD, theyre the problem with engineering and its terms

[leeminardi]

I was glad to see doug k's (post #8) post where he states “…you must edit the font to enlarge the symbol to be 1.5X the letter height”

Many years ago I worked for a CAD vendor and had the task of creating a vector based font for dimensioning and noted the obscure fact that many True Position symbols have a height 1.5 times that of text height.  AutoCAD ignored this requirement in its dimensioning fonts.

From Fig. C-1 of Y14.5

http://www-eng.lbl.gov/~shuman/NEXT/ANGEL2/ASME-Y14-5M-2004-Dimension-Ing-and-Tolerancing.pdf

d0.JPG

and from page 10

d1.JPG

[RobDraw]

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@Anonymouswrote:

Dont even try, def dont get used to doing it the wrong way by people who never used it outside of CAD, theyre the problem with engineering and its terms

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The problem with this is that people think the way they are used to doing it applies to every one everywhere, globally. The fact is that it differs by trade and geographic location. 

[Mayra.Moyles]

I get that the Diameter symbol precedes the value, but why is it in a different font as my Dimstyle? a little frustrating.