basic dimensioning of holes, c'bores & c'sinks per ISO standard 2

[benensky]

I am new to ISO drawing and have a question on dimensioning holes. What standard do you use? Granted I could purchase the, "ISO Standards Handbook - Technical drawings" but it is expensive and has standards I will not use and do not need. I am asking for guidance on the ones I will use.

I have bought a couple books on ISO drawing and have gotten conflicting information. Therefore, I need to buy the standards to see for myself.

One situation I have is holes on a bolt circle. Do you call out the hole and the bolt circle diameter separately or can you call it out all in one note. Please do not tell me what you do. I would like to know the standard you reference for this.

A second situation is that of counterbores and countersinks. ANSI has shifted to symbols for this and what I understood is that ANSI was shifting to symbols to be more like the ISO standard so that eventually one day the standards for technical drawing will be identical. In Simmons & Maguire’s book Manual of Engineering Drawing to British and International Standards they still use the truncated words C’Bore and C’SK. Another book I purchased, Paul Green’s Mechanical Engineering Drawing Desk Reference; Creating and Understanding ISO Standard Technical Drawings does not use symbols or truncated words but dimensions the diameter of the counterbore and depth and separately dimensions the hole. In the Technical Drawing section of the Lehrmittle Europa Technical Book Series Mechanical and Metal Trades Handbook (the book that the German company that owns us and requires us to draw to ISO standards gave us to use as a guideline) has an abbreviated way of calling out countersinks. For example, you could call out a countersink by putting this at the end of a leader which points to the countersink, “Ø10x14U”, where 10 is the diameter of the hole and 14 is the depth. However, I noticed that that is to DIN 6780 which is not an ISO standard. From what I can tell, this method will not be recognized universally by all people using ISO standards. Does anyone know what ISO standard defines how to dimension counterbores and countersinks?

I have more questions but I will ask them later in the thread if I get some good feedback.

 

[KENAT]

Most users on this forum are working to ASME but some do have familiarity with ISO. I used to work ISO but didn't know it as well as I now know ASME.

Take a look at the FAQ section especially faq1103-1044

thread1103-130938 (British Standards invoke ISO) & thread1103-214348 may be of interest too.

http://www.roymech.co.uk/Useful_Tables/Drawing/Drawing.html

is a pretty good ISO info source but I don’t’ see much detail on countersinks.

The table in ASME Y14.5M where it compares ISO & ASME standards indicates that the csk, cbore & depth symbols are only proposed for ISO, I don’t know if they’ve been accepted in the 14 years since 14.5 was last updated.

http://www.tec-ease.com/gdt-terms.htm

shows you what the ASME symbols for these are.

http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=37365

http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=9993

May be relevant but I’m not sure if they’re specifying the tool rather than the feature.

Sorry if the above doesn’t really answer you, turns out that maybe it’s a very good question.


KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at

http://eng-tips.com/market.cfm?

 

[ctopher]

A quick forum and Google search:

http://www.draftingzone.com/shoppingzone/6-1.pdf

thread1103-197198

ASME Y14.5M-1994

Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion

 

[KENAT]

ctopher, both those threads are pretty ASME specific, the OP is asking about ISO specifically.

KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at

http://eng-tips.com/market.cfm?

 

[ctopher]

I know. I just did a quick search. Didn't have time to do a detailed search...and I figured you were already on it.

Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion

 

[dgallup]

If your German company is like the French company I used to work for, they think they have a standard but they really don't. The French company didn't reference any standard on their title block. When I asked them how to interpret their drawings they said "We all go to the same schools & are taught the same way so we all understand the same. It is all ISO." So I gave them a little quiz & got totally different answers. The head of the department promised to come up with their standard but never could.

The problem with ISO (which we use) is that it is made up of dozens of little standards. They are not grouped logically, may be updated independently at any time and sometimes are in conflict. You just have to buy them & go through them one by one then throw 75% of them away.

Some of them are nearly unusable and absurd like 8015 & the latest surface finish spec (who's number I forget at the moment). Our solution was to write our own standard stating exactly which ISO specs we use and any exceptions. For example, 8015 lets you use a stipulate the envelope principle per Y14.5, over riding 8015's deeply flawed Fundamental Tolerancing Principle.

We do use the Y14.5 symbols for depth, countersink & counterbore.

 

[benensky]

Thx for all the replies
1-KENAT I like the all cap’s. That shows you are a real designer, not taking the cap’s lock off since you are creating text in drawings most of the time). Are your recommendations from experience?

2- KENAT Do you know if the c’bore and c’sink standards deal with technical drawing or how make the c’bore and c’sinks? Have you used them?

3-ctopher: Thanks for the post, however they are ASME standards (which I know and use). I hope you do not feel I am putting you down since I appreciate you taking time to respond to my post!

4-dgallup: Misery loves company and you are confirming what I already suspect. I take it since you are using ASME Y14.5 symbols there is no definitive standard in ISO on how to dimension c’bores and c’sinks. Therefore, at this moment I conclude that following Paul Green's Mechanical Engineering Drawing Desk Reference; Creating and Understanding ISO Standard Technical of dimension c’sinks and c’bores is by dimensioning each feature (like depth and diameter, angle) discreetly is correct. Otherwise, you are following house standards. This means, that any other way may not be understood by a shop trying to use the ISO standards to interpret our drawings. I need a clear way of defining thing sticking only to ISO standards since we send drawings to Brazil, India, Germany, Ireland and other countries all the time and we are claiming our drawings are ISO drawings.

5- dgallup: Your statement, “You just have to buy them & go through them one by one then throw 75% of them away,” is what I may end up doing.

6- I want to buy one more book, “Engineering Drawing for Manufacture (Manufacturing Engineering Modular Series) (Paperback) by Brian Griffiths” I hope this will clear things up. It states in the product description, “The information contained in an engineering drawing is a legal specification, which contractor and sub-contractor agree to in a binding contract. The ISO standards are designed to be independent of any one language and thus much symbology is used to overcome any reliance on any language. Companies can only operate efficiently if they can guarantee the correct transmission of engineering design information for manufacturing and assembly.” I will let you know what I think of this book.

7- If there is any other ISO drawing gurus out there to point me directly to what standard to use for dimensioning and noting bolt circles, c’bores and c’sinks per ISO standards it would be appreciated.

 

[KENAT]

1. As I recall back in the UK we used the term CSK a lot, I think we used CBORE too. However as you mention, these may not translate as well for non English users of the drawings. I'm not sure I really made recomendations above, just tried to give you some reading;-) Thanks for the compliment by the way, sadly I don't do much designing myself these days, mostly correcting other peoples drawings.

2. I don't know if the 2 specs explicitly define how to detail C'bores & CSK - hence my disclaimer. I may well have looked at them, or their British Standard predecessors back in the UK but I can't remember details.

I've got to say having worked to both ASME & ISO (Via BS8888 which is like a compendium of the relevant ISO standards) the ASME is simpler - 90% of what you need is in the one standard 14.5 and there's only a handfull of other directly relevant drawing standards as opposed to the dozens for ISO.

Good Luck

KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at

http://eng-tips.com/market.cfm?