I am fascinated and have a question for you experts.

We run Peak parts which have a lathe turning op with many different diameters and several depths also. It also has a radius on the part about 1/2 inch too. I can not post a picture because it if forbidden to photo any part we make per customer rules and contractual requirements for protection of their products. The mill work places six slotted steps for clearance for bolts and have tapped holes in each of them . On the flip side mill op we cutout a slot and then match up six counter bores which align to the other six previously done on op 1. My question is whether it is possible to make this part using additive technology even including 6-32 tapped holes (Tapped from the six holes and slots .2 deep on first op side) that are smooth and gage correctly or would it be more like make the lathe type part on a 3d machine and then setup to cut the other things? Plus would the lathe part done in the new process be profitable to make and would it be nice and concentric , parallel, and better finish than a lathe might provide. I could imagine certain things are better done on mill or lathe and yet I do not understand where the 3d printing has it's strength and profit strengths. Any enlightenment would be greatly appreciated to educate me about this amazing technology. Thank you in advance.

There's a few things you should research:
-whether PEEK is a material that can actually be processed at this time through an additive process. It's a pretty high-temp material.
-what the match is between your tolerances and the available tolerances achievable by 3D additive plastic process. I might guess that this is a closer tolerance part than additive process can create as a finished part, considering that it is a PEEK part. The 3D printing gear cannot do the job of a lathe in the precision arena, at least at this time. The finish might be nicer as an essentially molded part rather than turned.

The tapped holes I am certain cannot be done by 3D printing currently.

PEEK can be 3D printed by selective laser sintering. What you should consider is whether porosity is acceptable. I am not sure of the specs but 3D printed parts, particularly from selective laser sintering, might have a degree of porosity which might be unacceptable for the application.

Also I am not sure if most commercial 3D printers nowadays can achieve the lever of precision and part tolerances that is capable on a CNC mill or lathe. For example, lasers on the 3D printers are controlled by optomechanical devices, so forming a circular shape by sintering finite sized grains together (hence inherent roughness) might not be as superior as cutting parts in a lathe with a rotating spindle. There is inherent geometric advantage to lathing circular part geometries on a lathe, than interpolated circular part geometries from a laser scan controlled using mechanical control that is not geometrically circular in motion. Sort of like CNC milling a circle is not as good as lathing it because its an interpolated circle.

I think 3D printers are probably good right at this present moment in technological progress to be used to make rough stock that you can then put in a precision lathe or mill operation to do finishing passes on to get to dimensions if the specs call for it. Saves alot of cutting steps without need for roughing stock. Might save on material cost as there is less wasted material removed needing to scrap or recycle.

I think thread forms can be 3D printed. And they should probably work too.

But here is the catch, these 3D printers are really expensive. Those EOS SLS printers cost upwards of a million dollars. Probably cost prohibitive unless you have the kind of scale that makes such an investment possible. I guess you can farm out the work to people with those 3D printers capable with working with PEEK. But then how the economics and logistics/time works out is another can of beans that needs to be figured out.

Your post title will probably cause it to be locked. Read the rules. you have 541 posts, you should have it sorted out by now.