How much weight can a metal stud hold?

How much weight can the bars in the train car that people hold onto to prevent from falling over hold?

• You know, those metal bars. For instance, If I wanted to hang upside down, like you always did as a kid on a bar with the bar in your knees- would it hold my weight? at 125 lbs?

• Answer:

  I think you mean grab irons. They are way, way heavier than you are. Railroad passenger cars tend to weigh around 70-80 tons. You would be like a fly landing on an elephant's back. And to be honest, no I don't know because you weren't specific enough in your question.