What types of robots are used in manufacturing?

My answer to this question partially answers this question.

They are generally very expensive, but you can find used ones for sale. The expensive part is the robot controller, not necessarily the robot itself. Still, they will be the cost of a small car, at best. They range in size from relatively small to very very big. The smallest ones are used to assemble circuit boards and can move so fast they are just a blur, but the capacity is low. The largest one I have heard about can lift a car. A normal commodity 6 axis robot has around a 20 kg payload, and could easily injure or kill a person. When we install them in factories, we have to put them behind barriers that prevent humans from ever coming within reach. There are special safety systems that remove power to the robot if a door is opened for maintenance access. In cases where the operator of the machine has to place parts inside, we usually employ light curtains which drop power to the robot actuators whenever a person has their hands inside the unsafe area.