China has skilled machinists, probably more than the US has.
We shouldn’t be importing:
1. stuff that can be made and packaged by automated equipment
[we should only be importing high comparative advantage products]
2. ferrous products for motor vehicles
[we export few cars - tariffs on automobile grade steel won’t hurt US automakers]
3. aluminum alloys for aircraft
[we need the absolute ability to build warplanes]
4. inputs to make plastic products
[this stuff is made at industrial scale]
5. life-saving drugs and their precursors
[so our sick people can’t be held hostage by anti-American governments]