Minecraft wiki entry for Iron_Bars, associated text: In Java Edition, a 2×2 area made of iron bars can make a square-shaped hole big enough for the player and most mobs to fit through, but not rain, water, etc. that can be used as an easy entrance for an underwater house, and even an exit if pistons are used. Glass panes work in the same way.
If a sign or a painting is placed on iron bars, it appears to float in the air.
Despite apparently being thin enough to do so, iron bars do not let a ghast's explosion touch the block beneath them as long as the block is protected from other angles of the explosion affecting it.
If an iron bar is connected to a block and a rail is placed on the block, the top texture of the iron bar disappears.
While curing a zombie villager, iron bars placed nearby speed up the healing process. The same happens with beds, and both these things occur in the stereotypical prison cell.
Arrows cannot be shot through iron bars.
Because iron bars are 1 block high, the player can normally jump over iron bars, unlike fences.
In the code, iron bars are known as fenceIron.[verify]