I need a cylinder or 12 sided Polygon perforated for ventilation except for .5" margin.   5.27" long 6" diameter.

Need it made with sheet metal, lapped .3 or so at seam so it can be riveted and tabs for mounting bent toward center at 4 evenly spaced locations on each end.

I've tried just about everything I can think of and it seems the holes are not compatible with bend lines.  I was able to get it bent by skipping holes instances where bend lines occur.

What am I missing?  How can I fool the program into thinking there's a solid surface long enough to get it bent and still have holes.

Jerry