Y T  post     

Fence Post

A steel fence post, also called (depending on design) a T-post, a Y-post or a "Star Post", is a type of fence post or picket. They are made of steel and are sometimes manufactured using durable rail steel. They can be used to support either barbed wire, or woven wire mesh. The end view of the post creates an obvious T, Y or other shape. The posts are driven into the ground with a manual or pneumatic post pounder. All along the post, along the spine, there are studs or nubs that prevent the barbed wire or mesh from sliding up or down the post. While T-Posts are more common in the United States, Y-posts and Star Posts are more common in Australia.