Hi all, I would like to simulate a product which contains 2 parts, one is a screw and another is a cap which serves as a bolt. The screw size is different from typical screw. It is very large and is designed by ourselves. The only thing I would like to know is the axial load and compression stress to see if the screw and bolt is able to withstand huge axial force. The design is pretty similar to that of a jack screw. I have several question regarding the simulation.

Should I simulate it alone or with the bolt as well?

Can anyone list the steps of simulating the bolt connection in my case? I have tried few times but I am not able to pick the teeth surface. I simply do not know how to simulate it.

Thanks a lot. Attached are the files and picture of them.