Anyone know the exact definition for the notation: TYPICAL or TYP? I have some old drawing that use them. I'm not sure where or when to use them, or if it is even a standard. Any info is appreciated.
 

Not standard, but are typically used.
I have seen ".25 dia holes, TYP". What does that mean?
I don't use it.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

As far as a textbook definition goes, I probablly could not give it to you, but the use of TYP is pretty simple. If something is Typical, say so...

1. in lieu of counting and giving the discrete number of instances.

for example if you have a sheet metal part where all the break radi is .5 in, you would leader one radius and annotate ".50 TYP".

or

2. If you have a detail that occurs in 6 places on the drawing, you can add to the detail title "TYP 6 PL" meaning that all six places are the same.

Bacically you are saying all the things that look like "THIS" mean "THIS"

Wes C.
------------------------------
When they broke open molecules, they found they were only stuffed with atoms. But when they broke open atoms, they found them stuffed with explosions...

TYPICAL or TYP indicates the number of places the geometry feature or dimension appears on a drawing It could be in ANSI/ASME Y1.1-1989 Abbreviations for Use on Drawings and in Text.

Best Regards,

Heckler
Sr. Mechanical Engineer
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Never argue with an idiot. They'll bring you down to their level and beat you with experience every time.

According to the latest standard, TYP is no longer used.

ASME Y14.5M-1994
1.9.5
1.9.5.1
1.9.5.2
1.9.6

"Art without engineering is dreaming; Engineering without art is calculating."
Steven K. Roberts, Technomad
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

Mango, really? Guess that's why I couldn't find it... Well thank goodness for company standards... (i guess)

Wes C.
------------------------------
When they broke open molecules, they found they were only stuffed with atoms. But when they broke open atoms, they found them stuffed with explosions...

Sadly Mad Mango is correct.  I got this pointed out to me by my checker a while back.

I used to use it a lot back in the UK, especially on things like chamfers and rads.

Thanks MM.
I knew it wasn't standard, but wasn't sure where exactly in the spec. It was OK in 1982 std.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

Thanks guys for the quick reply and info. MM thanks for pointing it out that it is no longer a standard. I will do a lil more digging to see it this applies to us anymore.

If your company is typ, it will.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

Actually, the 1982 spec says the same as the 1994 one.

"Wildfires are dangerous, hard to control, and economically catastrophic."

Ben Loosli
Sr IS Technologist
L-3 Communications

Thanks Ben. Maybe it was the one before 1982, don't remember. But, it was OK at a time.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

It's a hard habit to break to be sure.

"Art without engineering is dreaming; Engineering without art is calculating."
Steven K. Roberts, Technomad
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?

Way back in the olden days of yesteryear before computers typ was a callout used for items of symmetry. You can still use it today. I currently use it for descriptions on land surveys.
Regards,
Namdac

If you use TYP on a mechanical drawing for symmetry today, it would not be clear what is needed.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

ANSI Y14.5 used to dictate the use of X instead of TYP, but ASME Y14.5-1994 now states that X "may" be used, which seems like TYP is allowed once more.  It is still poor practice in my opinion, as specifying the number of places removes ambiguity.  As for symmetrical parts, any qty question is answered by the symmetry mark on the centerline.

ewh,
I agree!

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

If the machinist can not understand what the drawing says they obvously flunked the blue print reading course. I think my thirty years between civil,mech,elec, and aero I have never had anyone come up to me and tell me that they don't understand.
Regards,
namdac

I haven't either. But, I have received a lot of parts machined wrong and not per print.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

I have a hard time forgetting level 3 drawing training.  The purpose of a level 3 drawing is so that there are no questions or ambiguities of how to make a part based on the drawing, anywhere in the world (provided they know how to follow the standard).  All of the i's have to be dotted and the t's crossed, so to speak.  There can be only one way to interpret the drawing and assumptions are not allowed.
Using TYP, you are ASSUMING that the fabricator will be able to tell the difference between similar sized holes and won't put in too many or too few, for example.
While some things have eased up per the standards, that doesn't mean that they constitute good practice.

There should be absolutly no assumtion in what is relayed as the correct information if I call out a 3/8" hole (typ.) the machinist, manufacturer they should already understand what I am designing. If the fabricator does not understand time to get another Fabricator. A DRAWING SHALL HAVE ONLY ONE INTERPITATION. Rule no. 3
Regards,
Namdac

Here is an example.
If you have a plate with 10 holes. Five of the hole are the same, the other five are the same. One callout indicates DIA .25 TYP, the other DIA .375 TYP. Which holes are which?
I have seen this type of drawing a lot.
The correct way would be to use a hole table.
I have also seen a part that had one hole drilled, with a callout DIA .375 THRU, TYP. The machinist wanted to know where are the other holes?
Although the new spec says it's OK to use TYP, and is widely use, I never use it for clarity.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

My most common use of TYP is on sheet metal parts, where I have radii corners, I will usually call out one of the 4 corners and say TYP, instead of 4X or 4 PL. If I have anything else that could lead to ambiguity (sp) then I use the discrete callout method.

Wes C.
------------------------------
Light travels faster than sound. That's why some people appear bright until you hear them speak.
they found them stuffed with explosions...
[/i]

As I understand it.  The "TYP" statement was and perhaps still is an architecture standard and not a mechanical standard.  The "TYP" callout was often used in wall sections to reference typical or common elements of a section.  In mechanical engineering, you often see this callout on hole dimension and the like.  As mentioned in this thread, it’s not to any mechanical standard. The correct way to reference a dimension in multiple locations is to indicate the number of times that dimension is references.  For example, if there are three holes then you can mark a hole as 3X.

namdac,

Do your drawings state ASME Y14.5 as the standard for interpretation.  If not, and the drawing is civil, or architectural, or other, typ could be used and left to the interpretation of the users.

Even if it is to be interpreted to ASME Y14.5-1994, you could use it.  The standard states in para 1.9.5):

Repetitive features or dimensions MAY be specified by the use of X in conjunture with a numeral to indicate the "number of places" required.   (Emphasis mine)

Again, this does not make the use of "TYP" a best method to dimension.

ewh,

I don't believe that 'X 7' hardly equates to 'TYP'.

But if you are not applying 14.5, GO FOR IT.

ringman,
It would be 7X.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

It would be "7X" (... X 7 would indicate "... BY 7" and is covered in para 1.9.6), and the current Y14.5 standard DOES NOT disallow "TYP".  So yopu can be applying the standard and still use "TYP". I wish it weren't so, but oh well...

The standard does not address it but I subscribe to the policy that if it can be interpreted any other way than the intended way, don't do it. I find that 99 times out of 100 "TYP" will be more confusing and draw more questions than just simply writing "(some number)X". If it is on an old drawing, that is one thing, but if you are drawing something new and you put "TYP" on it, you had better make sure that there is no possible way to misinterperet it.

I agree.
If I am doing several changes on an old drawing that has TYP, I will request to change it from TYP. I have seen different part batches be a little different from the old drawing because of TYP from different vendors. Make it clear and don't use TYP to describe qty of features or parts.
The only time I would use it would be for example, if I'm making a custom thread and call out a thread angle. The angle would be TYP because qty of threads could vary.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

Wouldn't you still only have one, continuous helical thread?

Yes. But, I have had machinists question it for some reason. Adding TYP makes sense to them.
So, 99.9% of the time I do not use TYP.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

Chapter 1.1 of the ASME Y14.5M-1994 standard explains the purpose of the standard.

"This standard establishes uniform practices for stating and interpreting dimensioning, tolerance, and related requirements for use on engineering drawings and in related documents..."

To me this means that if it's not in the book and you conform to the standard, then don't do it.

Section 1.9.6 indicates that an X may be used to indicate multiple locations but there is no mention of the TYP callout.

I feel very strongly that the "TYP" callout provides room for error and misinterpretation.  Why would anyone use it when it is much clearer and accurate to state a multiple place dimension as 2 X or 10 X or what ever?

I agree with you TTRYON, but the previous version of the standard dictated the use of "X" instead of "TYP".  The current standard only suggests the use of "X".  "May" has a different meaning than "shall".  The standard establishes uniform practices, but fewer uniform requirements.

I personally don't like using "TYP". Though the 1994 version of the standard uses the word "may" instead of "shall", I feel that because a previous standard prohibited the use of "TYP", and it isn't explicitly allowed in this one it shouldn't be used. In most instances "TYP" is too ambiguous and there is almost always a clearer way to say what needs to be said.

I did just think of a way that I would be cofortable using "TYP". A detail veiw of an arrayed set of features, I MIGHT use "TYP" next to the detail name, but most likely I would just put a quantity number.

If it can be misunderstood, don't do it.  

Yeah Well I started Drafting WAY BEFORE 1982, so I'm afraid I'm stuck with the "TYP." notation! And in my nook of the world, nobody seems to have a problem with either! Just chalk it up to another "old timer" thing! *L*   ...Mark

A case of "That's the way we've always done it"?

Very common saying. A lot of campanies live by it.
I witnessed once an engineer getting fired for saying it.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

You know in retrospect I'm sure there are guys on this forum that have to live and breath the latest/greatest ASME Y14.what ever  ...because of the discipline & company  they have chosen to work in/with. And my hat is off to them! However there is always a 360 Deg. view of the world, and standing in your shoes and proclaiming your view is the only right way is not correct either! I myself work in a 100 year old oil field and have to deal with all kinds of people, with all kinds of experience, so trying to stay on the cutting road of the latest greatest rules may NOT benefit a project I might be on. So calling out a repetitious fabrication detail as "6 PLC.s TYP." maybe less confusing the "6X"  ...Shouldn't that decision be left in the designer/checkers hands, as to what they feel would more easily understood by the people that have to fabricate the details? My $0.02!  ...Mark

No problem with that, especially if you include the number.  You are right, however, that many of us work in an environment where our drawings have to be easily and universally interpreted, which is why we follow those standards.  It very much depends on the kind of industry you are working in.

In addition to Mark's comment, dispite whatever standard applied, Company or ANSI, it is always ok to state whatever one needs to in order to make the drawing clear and concise.  The standard provides an insiders shorthand that reduces the amount of annotation required, but it doesn't mean written language is prohibited if it is actually make the drawing more useful (to the user and the creator both).  I use "TYP" rarely, but when I do, it's in instanstances where counting a feature's specific occurances is just completely pointless.  Use of "TYP" should be encouraged when it's not reasonable to be waisting time trying to figure pit the qty when the results will be the same regardless of however the quantity is called out.    

Good points.
My argument is, if everyone followed the same standards, we wouldn't be having these discussions.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

fcsuper,

If you don't have the time to verify the specific number of times the feature is required, how or why should anyone else subsequently involved with the manufacture or inspection be expected to verify the same information.

fcsuper, won't most 3D cad systems work out the qty for you?

Otherwise you need to verify it manually so it's a good cross check.

That said I used to say TYP but now no longer do.

ringman,  it could be suggested there is an over simplification by the point made in that statement.

KENAT, Depends on the scenario.  

The general thing is that TYP is understood by those who use it (creator and fabricator), whether it is specifically listed in a particular standard or not.  Misusing it would create confusion, but misusing any annotation does that.  The whole discussion on this is just academic.

I was thinking TYP on assembly drawings but I usually used it on parts drawings with hindsight for things like chamfer in which case the CAD probably wouldn't work it out for you, so ignore that bit.

I'd debate about it being academic, the first post was asking what TYP meant so obviously it's not universaly understood.

If something is defined in a standard and you reference that standard most confusion should be removed.

"My argument is, if everyone followed the same standards, we wouldn't be having these discussions. "

When i went to school the use of 'TYP.' was the standard and it was taught. My problem with the so called 'standards' is that if its all kept a secret unless you spend $1000, then it isnt really a universal standard. Its a standard only to those who subscribe to it.

Of the 6 companies I've worked for, only 1 has purchased the standards. And they dont update it, cause that costs more money. So if a standard changes, it goes unknown.

If standards are truely meant to be used by the masses as a universaly accepted standard, they need to be made available to the masses. The cost of publication and running the burocracy behind it should come from other sources.

Just my $.02

-------------

Randy

Gee Wiz can we quit beating this horse to death. I mean come on, if you can't find a copy of ansi 14.5, go to the library or have them send you a copy.
Namdac

That would be ASME Y14.5 1994

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

Chris,
Your sir are a pip. Funny too.
Namdac

namdac,

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

I use TYP on a drawing to indicate a rough dimension.  Such as a radius or chamfer which acts as relief and I am not concerned with having the dimension be exact or even fall within the given tolerances. For example, I might call out 1/8"TYP, meaning 'approximately' 1/8".

'approximately' can mean anything to different machinist, especially if converting from fractions.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

So if you had a number of radii that had to be approximately 1/8 would the call out be:

.125 TYP TYP

It's this kind of mixed/different use that makes you wish there were standards for this kind of thing.

Why TYP twice??
If I wanted a dim of .125, approximately, I would show a loose tolerance. I always show a tolerance on all dim's. This way there is never a question and everyone knows the range the dim should fall in.

Chris
Systems Analyst, I.S.
SolidWorks 06 4.1/PDMWorks 06
AutoCAD 06
ctopher's home (updated 06-21-06)

My point was that we seem to have at least 2 definitions of TYP being proposed and that it is possible that you might want to use both in the same note/callout.

Hence my callout was saying.

.125 Approximately, in a number of locations.

I wouldn't use it that way I'm just saying that's where you could end up.

Jintag,

Your use of TYP actually falls under REF, generally denoted by parenthesis these days.  Never heard of anyone using TYP in the way you mentioned, nor would that be clear to anyone who reads your drawing.