Those sentences mean different things, and none of them use correct grammar.

PHANTOM LINES (in general) INDICATE THE OUTLINE OF PART AFTER MACHINING. "of the part being discussed" or "of all parts"

THE (specific) PHANTOM LINES (that are being discussed) INDICATE THE (specific) OUTLINE OF PART AFTER MACHINING. "of the part being discussed" or "of all parts"

THE (specific) PHANTOM LINES (that are being discussed) INDICATE OUTLINE OF PART AFTER MACHINING. "indicate the outline being discussed" or "indicate all outlines" / "of the part being discussed" or "of all parts"

PHANTOM LINES (in general) INDICATE OUTLINE OF PART AFTER MACHINING. "indicate the outline being discussed" or "indicate all outlines" / "of the part being discussed" or "of all parts"

If you use the correct "the" and correct plural form of subjects, there is no confusion. If you want to save the effort of typing an extra 3 letters and a space, then the meaning is not always clear.


So to answer the question, omit it when you don't care if the reader understands what you are trying to say.

To add, "machining" was used in a general sense in all of your examples. If I am aware that you are in the habit of omitting the word "the" then I can't tell if you are talking about the specific machining operation being discussed, or all machining operations in general.

If I get a print from you that uses phantom lines to show a bolt circle in a side view, then I am going to cut right through the whole part because you said that is what it means. Instead of a bolt circle, you'll get a part that is milled in a bunch of different pieces. Same with any features on the far side of a view.

"none of them use correct grammar"

Should be:

"none of them uses correct grammar"

- Steve

These look like drawing notes from a Casting or similar. Drawings have some conventions that may vary from typical grammar. Additionally for most industry segments working to ASME Y14.100 type standards use of Passive Voice is still common.

So, making above assumptions then in the interest of brevity I'd lean toward "PHANTOM LINES INDICATE OUTLINE OF PART AFTER MACHINING" though it may be worth looking at ASME Y14.8 (the casting drawing spec) to see if it uses similar text.

The purpose of the definitive article 'the' is to identify a specific instance of the following noun. So in answer to your question, the proper use of the word 'the' is when you have the need to identify a specific instance of associated noun. If that's not the case, then either omit the article or use the indefinite article 'a/an'.

==> Those sentences mean different things, and none of them use correct grammar.
Yes, the sentences mean difference things, but what are the grammatical errors?
Or are you considering ambiguity to be a grammatical error?

Good Luck
--------------
As a circle of light increases so does the circumference of darkness around it. - Albert Einstein

THE PHANTOM LINES INDICATE THE OUTLINE OF THE PART AFTER MACHINING ...

but seriously i'd use ... PHANTOM LINE(S) INDICATES OUTLINE OF PART(S) AFTER MACHINING

Quando Omni Flunkus Moritati

Steve got me.

The error is similar to what you described Cajun. Either lack of "the" to identify "PART" as specific or at least "a" to identify it as singular. If the note refers to multiple parts, then the error is lack of the "s."

I can guess that there are not multiple parts on the hypothetical drawing in question, so maybe there is no room for confusion no matter how it is written.

The outline of the part after machining is indicated by phantom lines.

Right the 1st time.

http://www.writersdigest.com/editor-blogs/question...

There is no specific standard regarding grammar used in drawing notes.

Nevertheless accepted practice is to avoid using "the", "a", and "an". This may have something to do with the fact that one standardized note was to be applied to several drawings having one or several features / outlines etc., so usage of "the" vs. "a" vs. nothing would eventually be compromised anyway.
In fact, it was not uncommon to have note in form of pre-printed sticker.

Kenat, I checked with Y14.8 Section 5 - not a "the" in sight

And after all we can agree the drawing note is something different from magazine article, and both are different from, say, instant messaging (shudder).
Different rules apply in different situations.

Since all of those examples are from engineering drawings, you should be aware that rules of grammar for sentences and written prose aren't the same as used for notes on an engineering drawing.

Part of the problem is that no one can really describe the meaning of the word 'the'. If you don't believe me, give a try yourself. Granted, you can describe some examples, such as been done here, as to when or when not to use it, but that still does not provide a lot of insight into exactly what the word 'the' means.

My wife, when I was in college, used to type (this was back in the late 60's before PC's) term papers and graduate thesis for other students on campus. She would get so frustrated when doing one of these jobs for someone who's first language was NOT English, particularly if it was someone from Asia or India, as they would consistently misuse, or more often it seems, NOT use the word 'the' at all.

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

The rules for use of "the" vs. "a" in English are often the opposite of other languages like Spanish, so a direct translation is often wrong.

'the' is a definite article.

Stimpinguy:

Should be as before, "None of them use"... Omit "of them" which is superfluous, leaving the crux of the sentence as "None use".

And to the OP, the original sentence should read "Phantom lines indicate the outline of the part after machining.".

Mike McCann
MMC Engineering

It's surprising at times how concise engineering notes can be. IMHO

MACHINE INDICATED THREADS IN ACCORDANCE WITH MIL-S-7742D.

does not convey any more than

MIL-S-7742D THREAD


Seems to me that as long as the reader does not over-think the possible meanings the correct intent emerges right off the bat. From the OP note variations I would go with this wording:

PHANTOM LINES INDICATE PART OUTLINE AFTER MACHINING

Let's face it; 'the' is the most commonly used word, with one authority saying it accounts for 7% of total word usage. A snapshot view of my own scribbles gives an average of 7.1%, but there are differences. In my feeble attempts at short story writing 'the' crops up just 4.7% of the time, whereas in few of my scientific papers we have 7.2%. This rises to 9.2% in papers I've downloaded from the web. Research papers are of course more formal than friction and that's also true of published standards. In a handful of ISO standards I have either written or helped to edit the definite article accounts for 10.2% of the wordage and one obvious reason for this is the use of the imperative voice in test procedures, for example 'Place the ends of the test piece into the jaws of the grips of the tensile testing machine'. Laboured perhaps at 30% but necessary to avoid misinterpretation. We're not writing prose. Now how do you explain why 'the' drops down to 6.4% in standard ISO vocabularies? Well, that's because the definite article is not allowed to start a definition. I was always correcting it. Finally a snapshot of patents gives a figure of 10.2%.

"place ends of test piece into jaws of grips of testing machine" ... no?

Quando Omni Flunkus Moritati