Right. This is similar to how bolted connections work. Bolted connections must be tight enough that, when loaded with a force pulling the bolted connection apart, the bolted surfaces still have pressure pushing them together. Wikipedia has a good explanation of this.
Yes, and bearings too. For a bearing that will work under heavy load, the balls have to be "pre loaded," meaning that they are actually deformed just a bit, so they don't lose contact with the bearing races.
All of these things are examples of structures held together by springs.
