Sheet-metal 2D drawing interpretation
Sheet-metal 2D drawing interpretation
(OP)
When showing a folded sheet-metal 2D drawing, is that dotted and solid line represent the folding direction?
I was told that dotted line represend bend down, solid line represend bend up. I agree with that. BUT I think this is only apply to unfolded drawing NOT folded drawing.
I was told that dotted line represend bend down, solid line represend bend up. I agree with that. BUT I think this is only apply to unfolded drawing NOT folded drawing.






RE: Sheet-metal 2D drawing interpretation
TOP
CSWP, BSSE
www.engtran.com www.niswug.org
www.linkedin.com/in/engineeringtransport
Phenom IIx6 1100T = 8GB = FX1400 = XP64SP2 = SW2009SP3
"Node news is good news."
RE: Sheet-metal 2D drawing interpretation
RE: Sheet-metal 2D drawing interpretation
TOP
CSWP, BSSE
www.engtran.com www.niswug.org
www.linkedin.com/in/engineeringtransport
Phenom IIx6 1100T = 8GB = FX1400 = XP64SP2 = SW2009SP3
"Node news is good news."
RE: Sheet-metal 2D drawing interpretation
Are you talking about the folded view?
Are your drawings done as projections, third angle or first angle?
The dotted line shows a hidden feature, consistent with the flange facing away from you. A solid line shows the flange facing towards you.
Get your drafter to show projections at the ends.
RE: Sheet-metal 2D drawing interpretation
Post an image of what you are talking about. I'm guessing you are seeing hidden or tangent lines.
RE: Sheet-metal 2D drawing interpretation
Here is what I created for the topic.
which one is correct? A, B or C?
RE: Sheet-metal 2D drawing interpretation
The 'extra' lines you show (both Phantom & Solid) represent the tangent edges of the bend extents, not the actual bend lines.
If I had to show tangent lines, my preference would be type A.
RE: Sheet-metal 2D drawing interpretation
To get a correct drawing view you have to remove the bend radii to get a sharp edge to show in the projections.
TOP
CSWP, BSSE
www.engtran.com www.niswug.org
www.linkedin.com/in/engineeringtransport
Phenom IIx6 1100T = 8GB = FX1400 = XP64SP2 = SW2009SP3
"Node news is good news."
RE: Sheet-metal 2D drawing interpretation
Please see another attchment.
Break guy thought that the dotted line is folding down (see B) as this is how he interprete the drawing, this is "universal standard".
To my understanding, dotted line is represent the tangent line, nothing to do with the folding up or down.
Kellnerp, previous drawing is to to discuss the dotted line.
RE: Sheet-metal 2D drawing interpretation
In SolidWorks, you have the option of not showing tangent lines, showing them with "font", and showing them as solid. On my sheet metal drawings, I usually show them as "font". The solid line makes no sense to me. I do not know if this is part of any standard. Often, it makes the drawing clearer.
It appears to me that your view B is showing the tangent lines with "font". This means that transition between the flat face and the curved bend is indicated by a thin broken line. I do not see hidden lines, another thing you can turn on if you want.
You can try a view C, with the tangent lines turned off, and the hidden lines shown. Perhaps that will make more sense to your co-workers.
RE: Sheet-metal 2D drawing interpretation
You are correct almost. In "B" the dotted lines are hidden lines in orthographic projection. Before the advent of 3D modeling, the intersection of the two surfaces would be shown as a line.
The rule is, pick the view with the fewest hidden lines as the front view. Hidden lines are hard to interpret and tangent edges are almost meaningless.
Tangent Edges
Clarified
TOP
CSWP, BSSE
www.engtran.com www.niswug.org
www.linkedin.com/in/engineeringtransport
Phenom IIx6 1100T = 8GB = FX1400 = XP64SP2 = SW2009SP3
"Node news is good news."