Can you imagine the double entendre conversations when someone asks one of these guys what he does for a living?

You gotta have big balls to do what I do. etc...

I've seen that screw-forming of nice consistent balls somewhere else but can't remember where. Some sort of pastry or pasta thing where precise balls of dough were formed into cups or shells or something. It was probably more for volume metering rather than the need for nice spheres but it was similar.