when making a model to then be CNC machined, do i need to draw the internal threads where the screws will go? or can i just mark in the 2D drawing something like M4x8?
No need to model the threads - that just adds to file size. You just need to specify the thread size. Some shops also want the class thread included such as 2A or 2B.
I create solids in Solidworks and tool path with Mastercam.
If the threads are tapped all you need is a call out.
If you need to thread mill there needs to be a spiral to attach the tool to, I find Solidworks is better at creating this than my CAM software.
Use the hole wizard to define the hole(s) in the part, then you can use the hole-callout tool in the drawing which will auto-magically input the necessary details.
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