Tangent line in a dimensional drawing

[bear9298]

tangent line, when appropriate and not.. drafting standards.

 

[drawoh]

bear9298,

Please define this clearly. Are you talking about drawing curved faces from the side?

Drawings and forum messages are means of communication. Clarity matters.

--
JHG

 

[DraftingMan]

bear9298,

Please see attached from ASME Y14.3-2003, paragraphs 4.6.5 & 4.6.6, highlighted.​

John H. Dunten, CD
Certified Drafter

 

[bear9298]

Thanks guys for your reply... appreciated.. Drawoh.. sorry for the lack of clarity.. in cad you can turn on "Smooth lines" and you get a line at the point of tangency where you have added a radii to a veridical wall and a horz. face. I'm an old timer (55+ years) basic drafting you never used tangent line in views where you are going to add dimensions because of the possibility of confusing the tangent line with the line to be dimensioned. You could use tangent lines in ISO views..
DraftingMan... thanks for the lead on ASME y14.3 got it.. Thanks Guys for you comments.

 

[TheTick]

I make the call based on which adds clarity. Usually omit.

 

[drawoh]

bear9298,

I am over sixty. I am pretty certain I drew the phantom lines in on occasion back when I was on a drafting board. In general, I agree with TheTick, except I usually leave them in.

--
JHG

 

[dgallup]

I almost always turn the display of tangent lines off. If I do display them I use a lighter line weight. About the only time I display them is when there are a multitude of fillets and no sharp edges to display. Such parts often display better with the fillets suppressed and a note to fillet all inside corners x.xx max or some such verbiage. For ISO views these days I find it much better to display a shaded image.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[TWJR]

I'm with TheTick. If they add clarity (like when changes in topography would otherwise not be seen in a view), put them in. If they don't add clarity (like when a part simply has corner radii and it adds a ton of extra lines), then leave them out. Definitely don't do what I see engineers do here sometimes; display tangent lines with solid lines. That tends to make things totally confusing.