When you hold iron bars in your hand, you will see that the top face of the last vertical line doesn't render, making it in fact 2D.
MC-221947
iron bars item model doesn't render all its faces
Resolved
Invalid
0
This particular face does actually render, it's just the angle of how you see it. For example, if you turn on view bobbing and start walking around whilst it's in your hand, you will notice that this face is visible. It can be seen in F5 mode as well. I've attached a screenshot. With that being said, this ticket can be closed.