A t bar is a device used to attach two items together, such as a beam or a pipe, for support or strength. It is often used in structural engineering and construction applications and is also known as a tee-stirrup or tee-bolt. The T bar consists of two plates, each with a hole in the center, that are connected at ninety degrees to one another. The two plates are then attached to the item they are reinforcing by running a bolt through the holes. This creates a secure attachment and allows the item to be reinforced without additional holes or welding.