Threads not appearing on G-code/Slicing Software

[Anonymous]

I added threads to a cylinder to 3D print and when I looked at the previewed print, it showed no threads on the g code can someone explain why? 

I attached picture of what I see on my slicing software and the .f3d file of the cylinder.

The slicing software I use is Simplify3D and IdeaMaker (threads don't appear on either) 

Thank you. 

[jeff_strater]

see the response on the duplicate post:  threads-not-appearing-on-g-code-slicing-software

[ambitionHost]

interesting