Engineering Drawing Requirements

Refer to the ASME Y14 series of standards. There are individual standards published for nearly every conceivable engineering drawing application. The ASME website lists the title and brief description of each standard. Look through and pick out the ones that apply to your situation. Some good basic standards to reference are:

Y14.100 - Engineering Dwg Practices

Y14.1 - Decimal Inch Drawing Sheet Size & Format (also available in metric version)

Y14.2 - Line Conventions & Lettering

Y14.5 - Dimensioning & Tolerencing

If you want to take the easy way out, simply specify that all drawings must conform to ANSI Y14 and you'll probably get pretty good results. If you start buying standards for your own library, beware; a stack of references approximately 3" tall recently cost me about $1000. Good Luck!

ISO standards. There are local variants (the differences are often small).

We use the Australian standards AS 1100 Part 201 Mechanical Drawing which is almost identical to the ISO standard. The main variation I have seen is the tabular display of geometry tolerancing information (which really should be part of the ISO standard).

I think the ANSI standard differs in its use of symbols for geometry tolerancing.

Ask your national standards organisation what the local standard is. It will also be able to obtain the ISO standard for you if necessary.

It may also be useful to get a handbook or a good textbook on the subject for your drawing office.

Greg

The U.S. Government created an extensive series of engineering documentation standards for defense and aerospace contractors.

Although no longer officially in use, many small companies look to these standards if budgets are too tight to permit purchase of documents from ASME or other professional engineering societies. Many continue to be relevant to current commercial practice.

You can obtain a free PDF download of MIL-STD-100G "Engineering Drawing Practices" as well as a lot of other engineering configuration management and design process information at: www.Product-Lifecycle-Management.com

great! thank you soo much for the weblink, actually a lot of the entries was exactly what I was looking for. Thanks soo much.

There are many standards like ,ISO,ASMY,ASNI,DIN ,API,JIN etc.

Drawing requirements mainly depends on u r company standard which they r following r on u r counterpart.

Drawing standards are country specific ie. in the UK we use BS 8888, but you should also consider your customer base. If they are 'overseas' they might like to see drawings in their 'native' standard. If you use a CAD package to produce drawings they will often default to the set-up standard with regard to views, line types etc.

Never lose sight of the fact that the purpose of the drawing is to convey information to the user. There is no point in having a drawing that conforms to every known standard if it fails to tell the user what they need to know & your common sense will tell you what they need.

In addition to what has been previously stated, be aware of the following:

-Simplified drawings may be more appropriate for your company than those found in complex manufacturing, like aerospace and military contractors.

- Geometric Dimensioning and Tolerancing ( ASME Y14.5M-1994, formerly ANSI Y14.5M-1982) may be excellent shorthand and saves space in drawings of precision parts that have a lot of tolerancing issues, but it also requires a specialized knowledge and extra training to read those drawings and may be overkill for some industries.

- A good high school or college drafting text may be a good resource, possibly citing standards you may want to reference in your documentation and serving as a model for you of the basics. It could also indicate the level to which many of your employees are familiar unless they had prior corporate training in a more advanced or alternative drawing environment.

- Drawing standards do differ from country to country and modifications may be required to make them acceptable, including re-labeling and use of legends to explain symbology and the meaning of line-types.

One example of the above was when I worked for a US-German machinery company. The German engineers developed the drawings to German (DIN) standards. This include the use of 1st angle projections for views, whereas US (ANSI) standards use 3rd angle projection. If you don't understand what this means, basically it is the reference for the point of view taken off the main view for all other views. In practical terms, 3rd angle is the view one would have if one stood away from the part and looked back at a part represented by the main view.

In first angle, the secondary views are simply what you see if you rotate the part instead of moving the person's point of view. So the view to the right of a front view is actually the left side, which turns toward you when you rotate the part to the right. So right is left, top is bottom, etc., depending on which view you start with, although the "Back" view, opposite the "Front", is still the Back.

We did a "work around" by re-labeling the other views as Auxiliary Views and showing View arrows which re-defined them. After that, we learned to communicate better with our customers beforehand, so that we would create the Engineering drawing in the US to US standards if our customer required it. Surprisingly, some customers did not care, especially if there was any additional cost attached to re-engineering the documentation, and only request English language be used instead of German.

Thank you soo much and yes you are a guru. I am very familiar with 3rd angle and 1st angle projection and mil-std-100G. But the the company i'm working for now operates on a global scale and we don't need to get heavy duty into mil-standards and aerospace standards. The company is an OEM medical equipment manufacturer and would like to keep it as simple as possible but maintain a standard operating procedure that is suitable on a global scale. Eventually in the future I can see work projects in conglomeration with other companies in other countries. Simple documentation communication will be of the utmost importance so a "global" (international) engineering drawing standard would be great! Does anything like this exists!

As Americans should we create drawings in 1st angle projection and abandon 3rd angle? Should we convert to the metric system and abandon the American decimal system cause I believe we are the only one's using this system? Or should there be a compromising international engineering drawings standard?

How do you see the direction of communication of engineering drawings on a global scale?

Our company based in the UK deals extensively with American organisations (NASA, JET, LANL, SANDIA etc), we draw entirely in 3rd angle & have no problem in communicating. The drawings we receive back are mostly 3rd angle as well.

There are so many drawing standards, not only country to country, and industry to industry, but even company to company. I don't think you can go wrong by referencing the ASME Y14 series. A Drawing Requirements Manual containing most of these will cost you $885 bucks in hardcover through www.ihs.com (call IHS for quote in electronic form). You can also purchase an index only and buy just the standards which you believe pertain to your operation. The ASME Digital Store also sells many of these.

On the question of using metric versus inch, when I worked in the medical equipment field not too long ago, metric was not only quite accepted, it was basically standard with very few exceptions. This is probably due to the extensive use of it by physicians. Some components we needed were still manufactured in Inch sizes only, so we ended up with drawings that did mix inch and metric. So Inch sizes were called out, while millimeter was the default unit. For example, a base plate for an assembly might have many tapped and through holes. Some of them might be for Inch-sized threaded parts which required an Inch thread tapped hole, which would be noted on the drawing, while other dimensions would be unit-less. Also, many US manufacturers still only produce inch size versions of their products. On the other hand, some inch dimensions, such as bolt-hole patterns, could easily be converted to metric. Some drilled holes could even be given as a letter drill size ("J drill" for example) which can be looked up as inch and converted to metric if one wishes, however, for the aid of the machinist, it might be best left as the letter drill size. Dual dimensioning is acceptable as well, but can make busy drawings even more crowded.

On your other question, 3rd angle projection is so ingrained in US engineers and anyone reading a drawing in the US. I see no advantage to going to 1st angle projections, unless the majority of your "customers" are Europeans. Especially since there is such an easy "work around" by labelling the views and showing the direction of these views with arrows.

As a 'European' engineer I would say that we almost always use 3rd angle here.

Sorry! Perhaps I should have said "Continental"! I know the Germans, Swiss, and Italians, and probably the French, Spanish, and Belgians as well as others on the Continent, all use 1st angle (A DIN standard). I did not know the Brits were holdouts!

I wonder what the Irish use?

Just goes to prove my point that although there are definite advantages to going metric (as UK engineering and manufacturing has done), there is no such advantage to changing drafting standards from 3rd angle to 1st angle projection (although I'll bet some German or other "Continental" might challenge me on this!).

Perhaps this shows that we have a closer affinity with America than we do with most of Europe, despite what our government keeps telling us.

Simple, if you have to look at it twice after a few days of drawing it to understand what you've drawn, you have done something wrong. If the one who drew it can't understand it, nobody would.

Keep drawing as simple as possible and follow ANSI/ISO guide line.

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