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Drawing standards only for Military work
6

Drawing standards only for Military work

Drawing standards only for Military work

(OP)
We have a number of Engineers here who seem to think that the ASME drawing standards etc are only for military work and have no place in a commercial organization.

How would you respond?

Also If people want to make this some kind of survey of "We use the standards and are/are not Defense/Defence" that would be great.

KENAT, probably the least qualified checker you'll ever meet...

RE: Drawing standards only for Military work

No, they are not only for military. I have had commercial/military/medical/space customers require them.

Chris
SolidWorks 07 4.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 04-21-07)

RE: Drawing standards only for Military work

Definitely not only for military work.  The advantage of using them is (ideally) universal interpretation of drawing packages, and benefit commercial industry as well as military.  Properly interpreted and applied, different parts of complex assemblies can be made anywhere and all function correctly.  

RE: Drawing standards only for Military work

Also, ASME does not stand for American Society of Military Engineers.

RE: Drawing standards only for Military work

The Marines think it does, although they fall under the Navy. lol

Chris
SolidWorks 07 4.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 04-21-07)

RE: Drawing standards only for Military work

“The advantage of using them is (ideally) universal interpretation of drawing packages, and benefit commercial industry as well as military.”

I think you will find that most of the universe uses ISO.

RE: Drawing standards only for Military work

Most projects I have worked on, are a mix of ASME and ISO.

Chris
SolidWorks 07 4.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 04-21-07)

RE: Drawing standards only for Military work

ajack1,
Yes, we are in the minority, but it still provides for universal interpretation, provided the interpretation is per those standards.

RE: Drawing standards only for Military work

(OP)
OK, change to the OP.  Instead of specifically ASME then ASME Y14.100, ISOXXX, BS 8888 or equivalent industry standards.

Better?

By the way I have an opinion I just didnt' want to taint the discussion by putting it in the OP.  I want to try and get a better idea of what people think/feel.

KENAT, probably the least qualified checker you'll ever meet...

RE: Drawing standards only for Military work

Certainly for all the major European manufacturers in the automotive industry use ISO as do Ford owned companies like Jaguar, Land Rover and Aston Martin.

RE: Drawing standards only for Military work

I work for a multinational corporation (HQ in Germany) and none of our divisions have ever specified a standard to which they create or interpret drawings. So each division has their own opinion about each and every spec on a drawing - most of which do not conform to any standard.

So parts are not necessarily interchangeable and costs vary between divisions because everybody does things a bit differently. It is nuts and nobody within the corporation thinks it needs to be changed.

In the USA we have recently added a note to our title block indicating ASME Y14.5M-1994 and our own corporate addendum. Since most of our other divisions are European we probably should have indicated ISO but in the absence of any corporate guidance we picked what worked.

I am in support of ASME/ISO standardization in regards to drawings because it (ideally) facilitates communication of design intent. In the absence of some sort of standard, it is the wild west out there in regards to interpreting drawing (military or commercial).

We have had to deal with a lot of crazy nonsense because of everyone's opinions about GD&T rather than referencing a part of a standard.

RE: Drawing standards only for Military work

KENAT

I'm curious as to why the engineers would think that. Do they want to use/create their own drawing standard for use only in your organization?

RE: Drawing standards only for Military work

I had an internship with Dana and GM, and have worked in the commercial trucking industry for two different companies. All used/use ASME Y14.5 - 1994, Excpet the year of the standard might have been different. Regardless it used for the same reason as for GD&T, universal interpretation.

Out

RE: Drawing standards only for Military work

(OP)
I can't give a polite answer as to why they would think that, it would include words such as ignorant, uniformed, stupid, juvenile, immature, lazy...

Most of the Engineers don't want any standards, they want to do it however they want as standards ‘cramp their creativity’ and/or “take them longer”.

Historically this place didn’t have any real standards, a few CAD rules of use which were almost universally ignored and a few other procedures that were probably out of date before they were released because people didn’t’ work to them and didn’t update them to current practice.

Part of the reason my department was created was to improve the quality of documentation, we use adherence to Standards (both the ASME directly and where relevant our documented interpretation of them) as a cornerstone of this.

I bounced an assembly drawing for being a piece of **** on Friday.  I used the term every self respecting draftsman fears “redraw”, along with some specific requests and tips for achieving them.  It has blown up into a drawn out fight.  

This is related to several of my recent posts.

KENAT, probably the least qualified checker you'll ever meet...

RE: Drawing standards only for Military work

It is in such situations that I wish I were a contractor again.

RE: Drawing standards only for Military work

Quote (Kenat):

Most of the Engineers don't want any standards, they want to do it however they want as standards ‘cramp their creativity’ and/or “take them longer”.
So true! I think you will find this at a lot of companies.

Chris
SolidWorks 07 4.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 04-21-07)

RE: Drawing standards only for Military work

What does 14.100 say about the intent of the standard?

Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group

RE: Drawing standards only for Military work

(OP)
Nothing specific, the Forward is too long for me to type but:

Quote:

... provide common engineering delineation standards to aid the increasing interchange of drawings between industry, government, and other users...

I posted the below a while back which is a summary of some of my opinion on drawing standards.

“Industry Design & Drawing standards can be of significant advantage to an engineering company, they essentially define a standard "engineering language" and set of practices, customs, definitions etc.

Use of them reduces reliance on informal "tribal knowledge" since they allow any competent engineer (or related position) to understand the data without ambiguity. This allows any engineer to work on future revision of the data with less chance of errors based on misunderstanding, it also supports verification (checking) of the data with less chance of time-consuming misunderstanding thus producing better quality data. It allows manufacture of the item defined by the data to be outsourced with minimal chance of misunderstanding. This then supports increased outsourcing to increase through put without increasing manufacturing overhead. It also allows competitive tendering from a number of suppliers rather than relying on one supplier that has built up tribal knowledge of the item, leading to cost reductions.

While many of the standards have their origins with the military their aim was and still is to allow maximum rate of production for the best value using multi sourcing and competitive tendering (especially during war time). This is equally applicable to commercial companies and the standards have now been widely accepted by industry and in fact most are no longer controlled by the government but by industry bodies.”

KENAT, probably the least qualified checker you'll ever meet...

RE: Drawing standards only for Military work

"...in fact most are no longer controlled by the government but by industry bodies."  I'd say this sums it up.   Of course, the audience here is friendly to your cause.  :)

Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group

RE: Drawing standards only for Military work

I would have them to look at any of the Y14 standards committee or subcommittee personnel in any of the Y14 standards and they will see where these people worked at when the individual standard was approved.  Here are some companies: Dimensional Control Systems, Inc.,Boeing, Monroe Community College, Purdue University, Naval Surface Warfare Center, General Motors Corp., Ohio University, Caterpillar, U.S. Department of the Army, Sandia National Laboratories, U.S. Department of the Air Force, U.S. Department of the Navy, United Defense, National Security Agency, Raytheon Co., Lockheed Martin Aeronautical Systems, United States Postal Service, Dupont, Fluor Federal Services, Oklaloosa-Walton Community College, The American Society of Mechanical Engineers, ABB Combustion Engineering, Inc., MTD Products, Inc., Gary Whitmire Associates, Hutchinson Technology, Inc., Eastman Kodak Co., Copeland Corporation, Steelcase, Inc., L. W. Foster Associates, Inc., Motorola, Pratt 8 Whitney CEB, ASEA Brown Boveri Combustion Engineering Systems, Rexnord Corp., Santa Cruz Technology Center, National Standards Educators Association, Westinghouse Electric Corp., Deere b Company, John Deere Dubuque Works, E-Systems, Inc., University of Cincinnati/GE Aircraft Engines, Polaroid Corp., Geometrics Consulting, Williams Creek Graphics, Ford Motor Co., Los Alamos National Laboratory, Garrett Turbine Engine Co., Shepherd Industries/Northern Illinois University, Lawrence Livermore National Laboratory, McDonnell Douglas Corp., El Camino College, Texas Instuments, Harper College, Daimler Chrysler, National Systems Management Corporation, Logicon information Systems and Service, Illuminating Engineering Society, Gleason Works, Avondale Shipyards Inc., Cessna Aircraft Co., 3M Co., Xerox Corp., and Infrared Industries.








 

RE: Drawing standards only for Military work

(OP)
Good point vigil.

There is a strong defense bias but plenty that aren't, the likes of Xerox & Kodak jump out as being in vaguely related (very vaguely) type of industry to our place and using the standards.

KENAT, probably the least qualified checker you'll ever meet...

RE: Drawing standards only for Military work

Some places make a distinction between drawings that will leave the building, and those that never will.

Drawings for internal use may refer to standards that are not published externally, e.g. are hung on the shop wall, and may be simplified in nonstandard ways in accordance with internal custom that has evolved to suit the particular business.

BEWARE OF DISTURBING AN EVOLVED SYSTEM.  It may be working very well indeed, but as the new guy, you wouldn't necessarily be able to tell.

It may be in a company's commercial interest to make drawings to be sent out intentionally obtuse or misleading, because they stand a good chance of falling into the wrong hands.

The military insists on easy to read drawings because the person interpreting the drawing may also be under fire at the time.  

Not everyone has the same set of incentives.

Mike Halloran
Pembroke Pines, FL, USA

RE: Drawing standards only for Military work

(OP)
Mike, generally I agree that when new to a company you shouldn't go out guns blazing to change things.

There were no meaningfull standards, that's part of the reason my department was created.  So when you've been hired to change things, leaving the Status Quo isn't an opton.  That said I do believe my department made mistakes in this area in the first few months, some of them before I was hired, in not properly gauging what some common practices etc were.  

The 'system' wasn't working: high rate of mistakes/rework on parts; stuck with vendors because they were the only ones who had worked out what the chicken scratch drawing was meant to say; lots of ecos to correct drawing errors etc.

The system wasn't evolved, people made up rules as they went along.  If you asked 5 different people how to do something like an eco you'd get 5 different answers, and I don't mean just personal preferences.

Been here almost 2 years, not sure if I count as the new guy any more.

Your point about drawings being deliberatly misleading is something I've thought about.  At least one vendor we use also supplies a competitor.  However, surely even in that case the drawing needs to be clear enough for the vendor to make it (mostly talking machined parts)?  Isn't this kind of concern better dealt with by having NDAs etc?

Quote:

The military insists on easy to read drawings because the person interpreting the drawing may also be under fire at the time.  
while it may just about be true for higher level schematics/assemblies etc I don't think its a major reason.  I'm pretty sure the main reason is so that any competant organization can make it from the drawing.

KENAT, probably the least qualified checker you'll ever meet...

RE: Drawing standards only for Military work

I don't really agree with Mike Halloran's premises.  The falling-into-the-wrong-hands point is a matter for the legal, IT, facilities and/or security departments (depending on the company and the extent of the breach).  Besides that, I don't buy that any tribal system is entirely cryptic enough to abate illicit use of a drawing that has fallen into the wrong hands.  

Anything that makes it easier for someone to use under-fire is certaining going to be useful in creating economic efficiency on the homefront (which is what the ANSI standards did/do).  This goes for internal and external drawings.

Also, if a system is severally broken, then holding to closely to it when trying to create a system that works will only make the problem worse and prolong its faults.

Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group

RE: Drawing standards only for Military work

MikeHalloran,

   I doubt very much that engineering drawings, particularly mechanical ones, are read by people who are being shot at.  The real problem is that the parts and assemblies may be critical, and that the military does not want to rely on you as the supplier.  I do not see how you can generate Level_3 drawings without following a standard that defines what all the notations on the drawings mean.

   If the drawings stay in-house, you can get away with a fairly eccentric drawing procedure.  It may even be a good idea for some industries.  When your drawings go out of house, you have a contract or a PO that states that parts are to be fabricated to drawings such and such.  These drawings are part of the contract, so they have to be clear and unambiguous.  A rectangular plate with plus/minus dimensions for the length and width actually is ambiguous unless a standard explains what it all means.

   ASME Y14.5M-1994 meets lots of non-military requirements.  I do not see it as something exclusively military.

   There is a lot of interesting history on military requirements.  Read up on the Thomas Morse scout planes.  Also, read up on the Brewster Aeronaughtical company.  

                        JHG

RE: Drawing standards only for Military work

I wanted to make the point that there are valid reasons for making drawings that are not standards- compliant, or easily understandable, or correct, and that a unilateral decision to make your company's drawings 'better' could be a career decision.

Yes, the military needs drawings that are good enough so that any low bidder can make a good part ... because the military has put most of its suppliers out of business.  In the process, they lost the information that didn't appear on external drawings, and the information that didn't appear on _any_ drawings.  ... All done to promote competition.

Competition didn't need promoting.  An NDA is not going to prevent an unscrupulous customer from sending your perfect drawing out for bids.  He needn't fear you, because you won't be able to pay your lawyers.

In Kenat's case, the company appears to be just FUBAR.  Any company that expects a checker to change the corporate culture is doomed.  

Mike Halloran
Pembroke Pines, FL, USA

RE: Drawing standards only for Military work

My thought is not directly in line with the OP, but MikeHalloran had a (sadly) astute comment as his last line:  "Any company that expects a checker to change the corporate culture is doomed."

I have to agree, except it may be KENAT and his team that is doomed in such an atmosphere.  I think KENAT will face a continual uphill battle unless the senior executive staff is constantly educating, motivating and directing the engineers to change to the standards being created by KENAT's team.  KENAT, I hope you are not out on a limb like that.

To your OP, let me say that we are an entirely commercial organization (on the engineering side, on the mtc side we do a very small amount of DOD work at one location out of about six), and our drafting standards are based (loosely, but still based) on ASME.  I hope that helps a bit.

debodine

RE: Drawing standards only for Military work

(OP)
FUBAR, that may be what you think but I couldn't possibly comment!smile

Out on a limb, varies by the day of the week and what mood the VPs etc are in.

Doomed, possibly, perhaps probably.

Gotta go, may post again later.

KENAT, probably the least qualified checker you'll ever meet...

RE: Drawing standards only for Military work

KENAT

I feel your pain. I am unfortunately in the same rapidly sinking boat.

For about 20 years the company I work for never had any standards for drawings and checking was done by unqualified folks according to their own opinions concerning format and intent. In addition, mfg and QA use their own interpretations concerning GD&T to make and qualify parts. So who knows what was the real design intent and what we have manufactured?? This has resulted in extremely costly problems. So we have a huge mess on our hands.

Now this system (or more accurately lack of a system) is so darn ingrained that it is all but impossible to change. I even have the VP of sales arguing the finer points of GD&T with me on a daily basis - these are really fun "conversations".

The president of the company wants standardization (rightly so) and has charged me with the task. So we adopted ASME Y14.5-1994, state this in the title block, and are checking/drawing as closely as we possibly can to the standard.

But the organization overall is completely unwilling to entertain change of any kind even if it proves to make us more profitable and makes product easier to manufacture. Everyone would prefer we continue to make the same costly mistakes forever to avoid change and a system in a state of flux.

The common argument is "if you are going to make a change to one drawing, make it to all drawings at the same time". When we have over 1500 drawings, finite resources, and design responsibility for new product this is not possible unless we devote all resources to this alone. In this regard, we slowly revise older drawings when the time is right.

So what the heck to do when the president demands change, we follow his instructions, and everyone else fights us tooth and nail to the bitter end?

IMO this is a no-win situation. The president wants standardization but nobody else buys into it and training resources are not available to key people - so it is either going to be terribly painful or will flat out fail (more likely).

My personal strategy is to soldier on and remain committed to standardization and try to work with the other departments to bring them up to speed. I continue to make changes, check drawings, and generate new drawings according to our standard but I make it a point to spend the time to document and discuss the "why" of any aspect of these drawings in the simplest terms possible with whoever would like to discuss this information. Correlating formatting or interpretation problems related to engineering drawings with real world problems (sometimes extremely dangerous problems) tends to help drive home the point. I also try to push the economic advantage to management, this is really what they care about.

This is very difficult, painful, and time consuming. But I hope by educating everyone as best I can and stressing the advantages of standardization (or more accurately, indicating to each department how they stand to gain) I hope to eventually win support. Basically, I am salesman and evangelist for standardization and proper use of GD&T within our organization.

Will this work? Will I get burned out? Will I get fed up and quit or get fired? Who knows for sure but at this point I am not sure if the light at the end of the tunnel is a train or not. I do think that it is better to die on your feet than to live on your knees, so I will fight the good fight and see where it leads me (maybe to a different job that is less stressful).

Best of luck to you KENAT!!

RE: Drawing standards only for Military work

KENAT,

I appreciate you relating your experience, but I'm also fearful for your.  You are talking in some detail about your company.  I know you don't mention which company it is, but this could backfire.

That said my comment regarding this statement, "The president wants standardization but nobody else buys into it and training resources are not available to key people..." is simply that the President needs to be a leader and get people behind the decisions they are making.  Your job (I assume) should be made very easy by simply bring up his name every time someone tried to argue with you. :)

Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group

RE: Drawing standards only for Military work

(OP)
Thanks for your concern FC, may have said more than was expedient on 31st, good call.

However I think you may be confusing joebk post with mine.

Jobbk, good luck, I feel your pain.

Foolishly checked my mail from home earlier as I'd left something unfinished yesterday.  Appears someone is sawing the limb.  Same person who got the last Checker laid off, seems they didnt' like that checker doing their job and point out mistakes made on a product release that was, to use Mikes phrase, FUBAR.

Sure makes me want to do a good job.winky smile

However, this has gotten a bit off topic, thanks everyone for the replies sympathy etc.

KENAT, probably the least qualified checker you'll ever meet...

RE: Drawing standards only for Military work

KENAT,

Just to make it clear, this is what I was talking about:

Quote:

The president of the company wants standardization (rightly so) and has charged me with the task. So we adopted ASME Y14.5-1994, state this in the title block, and are checking/drawing as closely as we possibly can to the standard.

But the organization overall is completely unwilling to entertain change of any kind even if it proves to make us more profitable and makes product easier to manufacture. Everyone would prefer we continue to make the same costly mistakes forever to avoid change and a system in a state of flux.

Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group

RE: Drawing standards only for Military work

Kenat The Flag Bearer will fail in his mission unless his flag is borne on a pike.

Too allegorical?  Okay.  He can't effect change without authority.  E.g., the authority to fire someone, _anyone_, for not doing as the Prez says he wishes.  

Chances are he'll be ignored _until_ he fires someone, and makes it stick.

That could be an opportunity.  If all the incumbents really are too valuable to lose, consider hiring an actor to ingratiate himself with the status quo folks, become their point man, and be fired, as publicly as possible.

Mike Halloran
Pembroke Pines, FL, USA

RE: Drawing standards only for Military work

(OP)
FCsuper, that was joebk, not I.

Failure is indeed impending but we've been thinking that for almost 2 years and we're still here (except the laid off checker).

Authority to fire, they don't like to fire people round here.  Many people are treated with kid gloves and allowed to get away with murder it it's thought they have rare technical expertize.

One of the Directors did fire someone that refused to tow the line and ever since everyone in his departement has been trying to undermine him.

KENAT, probably the least qualified checker you'll ever meet...

RE: Drawing standards only for Military work

man, yup.  Ok, so my comment is for both of you. lol  I shouldn't do this when I'm half asleep. :)

Matt
CAD Engineer/ECN Analyst
Silicon Valley, CA
sw.fcsuper.com
Co-moderator of Solidworks Yahoo! Group

RE: Drawing standards only for Military work

Sorry for the soapbox but I want to emphasize that the drawing is a legal document between the manufacturer and buyer and should portray the end-item as succinctly as possible. Also there are uncounted reasons that it is unwise to use it as the sole manufacturing instruction.  Whether the mfgr is in-house or not should not concern the draftsman.  He should resist the temptation to "give mfg what they want."  I know it's tough because mfg pays the bills but I've seen too many drawings turn into detailed assembly instructions that would produce a very expensive product if given to a contract mfgr.

What happens if business conditions change and the machinists are so swamped with work that outsourcing is required?  Or what happens if the customer paid for the drawing pkg and took it to another supplier?  There is no room for "company quirks", unstated (yet "understood") requirements, gut-wrenchingly detailed "how to" notes, and so forth.

I had a checker tell me that the installation hole size for a captive fastener MUST be called out on the drawing because "the machinists like that."  I explained to him that the future may contain a scenario where the originally-specified fastener (called out on a separate parts list) was unavailable and that one from another mfgr would be used.  The new part may not be suited for the hole called out on the drawing.  I asked him to leave the "install per the manufacturer's recommendations" note and leave the installation hole off the drawing.  He wouldn't.  And this guy had thirty years of experience!

BTW I'm an engineer and not all of us are sloppy or cavalier with the drawings.  Maybe this is because I haven't always had a draftsman or designer to do the drawings for me.  For years I've had to do my job and theirs too (frequently at the expense of dulling my analytical skills).

Tunalover

RE: Drawing standards only for Military work

Tuna, I'd side with your checker.




Mike Halloran
Pembroke Pines, FL, USA

RE: Drawing standards only for Military work

MikeHalloran,

   I side with tunalover on this one.

   The note "INSTALL AS PER MANUFACTURER'S INSTRUCTIONS" tells the fabricator to read the manufacturer's literature and follow all the instructions.  In the case of PEM fasteners which I use a lot, this means that there is a hole size with tolerances, that the holes should not be deburred, and that you should not use a hammer.  Providing the diameter of the hole and other instructions implies that there is no need to read the literature.  

                           JHG

RE: Drawing standards only for Military work

(OP)
Tuna, you're preaching to the choirwinky smile  I strongly agree with your first 2 paragraphs.

As to the inserts:

Treated as an inseperable assembly I think I'd side with tuna (at least that's what my last checker taught me).

Treated as a separate machined component that the inserts are later assembled to then, I side with Mike.

I've worked companies that did it both ways.

I too am an Engineer (at least I have my bachelors), that's why many of the arguments about Engineers not needing/being expected to do it lose their impact on me.  That said I sometimes wonder about my analytical skills, but more with respect to potential future jobs than the ones I've had.

KENAT, probably the least qualified checker you'll ever meet...

RE: Drawing standards only for Military work

I've worked in places that did it both ways ... and other ways too.

Presence of a checker implies that you are mass producing stuff, i.e., the installer doesn't cut the holes, and the machinist doesn't press in the PEM parts, so you have to tell the machinist exactly what holes you want.

In a startup/ small craft shop, where everyone is an artiste, they get all huffy if you give them instructions... which they ignore anyway.  They will almost certainly prove to you that it is possible to install a PEM part with a hammer, then blame you for buying cheap knockoffs when they end up cocked or fall out.

In a union shop, they do exactly what's on the print, and no more.  Expecting them to read and interpret other people's directions changes their labor grade, so you have to pay them extra ... and provide a copy of the outside instructions with each lot's paperwork.

Mike Halloran
Pembroke Pines, FL, USA

RE: Drawing standards only for Military work

(OP)
No mass production here.  Howevever mistakes can be expensive and/or cause delays so we have the checking function.

KENAT, probably the least qualified checker you'll ever meet...

RE: Drawing standards only for Military work

MikeHalloran,

   I prepare fabrication drawings that call up thread inserts that are to be installed by the fabricator.  I do not get to see the intermediate steps.  If the inserts work okay, I do not care.  Presumably, if the shop follows the manufacturer's instructions, everything works.

   Obviously, if I were planning to install the thread inserts, it would be better for me to read the manufacturer's literature and provide complete call-outs.

   I cannot recall having problems with PEM inserts.   I have had problems with some helicoil inserts.  Eventually, I inspected the tapped holes with a thread gauge and I determined that they were oversized.  The fabricator's excuse was that they had used an old, dull tap.  Calling up the tap drill size on my drawings, another popular trick, would not have saved me.  

   In a truly mass production environment, would it not be logical for the fabricator to provide additional documentation and tooling for manufacturing and inspection?  The usual principle behind engineering drawings is that they describe what we will accept at our loading dock.  There is no reason to assume that manufacturer A would do the job the same way as manufacturer B, and we do not care.

                           JHG

RE: Drawing standards only for Military work

I forgot to mention a few other reasons why the INSTALL PER THE MANUFACTURER'S RECOMMENDATIONS or INSTALL PER THE ITEM'S GOVERNING SPECIFICATIONS is the right way to go:

A.  The drawing is tolerant of changes.  Change of a fastener would require only a change to the parts list.  The drawing itself would be unaffected.
B.  Invoking the fastener manufacturer's recommendations places the latest and greatest quality assurance provisions on the installation;  it requires the fabricator to keep an up-to-date version of the fastener mfgr's installation procedure at hand at all times.  Otherwise he may get complacent and use an installation procedure from 1979 while the design and installation procedure may have evolved since since then.  It's absurd to discuss this in the context of a clinch nut, but this practice becomes more influential as the fasteners becomes more complex, expensive, and expensive to install.

It all boils down to following sound principles and practices.  A good drawing promotes consistency and quality by emphasizing the end-item and functional requirements and leaving out rote process data like installation hole sizes.

It looks like MikeHalloran has succumbed to Manufacturing's propaganda.  Now that we've started breastfeeding the fabricators why don't we add a note that says "DO NOT DEBUR INSTALLATION HOLE"?

An assy may have threaded holes in it too.  Wow, I think we could REALLY handhold the fabricator there.  Let's call out the drill size for tapping into AL6061-T6.  That way, when we change the material to titanium three years later and we forget to change the drill size (SH7, Zone B6) then we can argue with the fabricator when he complains about using the wrong drill size for 27 pricey titanium parts.

I'm sorry to preach to the choir but we must LET THE FABRICATOR DO WHAT HE DOES (KNOWS) BEST.  A good fabricator doesn't need (or want) to be told what drill size to use for tapping a .086-56 UNC-2B hole a quarter inch deep in titanium.  If he DOES want the information then he's using inexperienced (cheap) machinists or has poor practices.  A good machinist has the information in his head or in a tattered up handout at his workstation.  If not then the traveler that goes onto the floor will have the information in the form of instructions from the Production Planner.

Resist the urge to complicate the drawings by adding all that process information to the drawings!

Now multiply these notes by the number of fabrication drawings a big project has and you end up with a set of drawings that would be very expensive to revise!

Tunalover

RE: Drawing standards only for Military work

(OP)
tunalover, while I tend to agree with you you are maybe a little harsh on Mike.

In the particular instance talked about in detail, i.e. installation information for captive fastener, there isn't a one size fits all answer.

If treating as an inseperable assembly then yeah, per manufacturers instruction.  However, not all drawing systems really deal/cope with inseperable assemblies as such, the one I worked to in the UK didn't so we tended to put the hole size etc on the part drawings while the captive fasteners were called up at the assy level.

Even then using the manufacturers instruction assumes that in between the creation and the drawing there is either a manufacturing/production/industrial engineer and/or a skilled machinist that can invoke & apply the manufacturers instructions.  

For a small shop creating their own drawings for internal use, there may be justification for puting the detail on the piece part even when treating as an inseperable assy however, I agree this is straying away from classical drawing practices and in most cases is a bad idea.

KENAT, probably the least qualified checker you'll ever meet...

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