General Drawing Question - Concave Circle/Hole?

[reddeth]

Hello all! I searched around for a bit but didn't find my answer, maybe I'm using the wrong phrasing? I need to draw a countersunk hole looking at it from the "front". From the side, this is easy, just draw the countersink angle itself. But how would I represent that from the front? The photo below shows what I have as a side/front (incorrectly labeled as top) view, is that correct? Is there something that should be done to "show" it's a countersunk hole?

 

Thank you!

 

Edited September 19, 2011 by reddeth

[Ryder76]

ortho.dwgThe pic of the side view of your 'concave hole' looks like a pipe reducer. Your 'top view' is actually a front view. Have you ever done orthographic projection? Not sure how to help you other than to say your 'top view' will be similar to your side view.

[reddeth]

Well I feel like an idiot - I did this all in a hurry and just realized I'm using the wrong term. I need to know how to do a countersunk hole, not a concave one (although I guess they're similar, but regardless...)

 

I had not heard the term orthographic projection before, or if I have I don't remember it; but I am doing an orthographic projection drawing and I had the labels mixed around (that's what I get for doing this in a hurry) - the "top" view in my image above is actually the front view like you said.

 

I'm not sure what you mean by it looking like a pipe reducer, unless you mean the split in the angled lines, which is because half the hole is obscured by the surrounding material (it's a punched sheet-metal part). I'm not sure if what I'm saying is making sense though, I apologize if I'm not explaining it very well.

 

Ultimately, I need to know how I would represent a countersunk hole in a sheet-metal part in the front view - or is the drawing I pasted above acceptable (despite being mislabeled)?

[Ryder76]

How about a hidden line/arc to show the indentation of the concave part and a note for clarity. The redlines show the projection from the other planes. On the hidden arc I just fudged it in - You would need to know the depth that it goes back into your 'hole'.

ortho.dwg

ortho new.dwg

[Jack_O'neill]

I agree with Ryder in that your terminology is wrong, but what you've drawn there is fine for 2d drafting if you make your side view in hidden lines. It will after all be in the material you're making the hole in.

[reddeth]

Alright, thank you both for your help! I just wanted to make sure that what I was drawing was correct/acceptable. Sorry about rushing through the original question and getting the terminology mixed up.

[Jack_O'neill]

There are any number of lisp routines available out there that will draw counter sunk and counter bored holes for you based on nominal screw sizes. A little digging on google will bring them to the surface i'm sure.