The welding at 2.09 is not the welding described by the text. The video is rotation friction welding, where the friction is between the two round pieces being joined and there is no tool piece in the weld. Friction stir welding is where a rotating tool is forced along a joint creating heat and mixing the two parts being joined.Some of these machine tools are being operated without guards. This only happens in places where safety rules don't exist. Fingers, hands, eyes are regularly lost operating such unguarded machines. Regulations are a good thing when it comes to protecting workers. Unionize peoples!