What is the name of the cylinder that is attached to the back of the moldboard and connected to the circle?

The cylinder referred to in the question is indeed the Blade Pitch Cylinder. This component plays a crucial role in adjusting the angle of the moldboard. By changing the pitch of the moldboard, the operator can optimize the grading process for various types of material and terrain conditions. Adjusting the blade’s pitch effectively allows for better control over the material being moved, whether it’s for cutting, spreading, or leveling.

The Blade Pitch Cylinder functions by tilting the moldboard forward or backward, which directly affects how aggressively the grader interacts with the material being worked on. This adjustment is essential for achieving the desired grading results, as different tasks may require different angles of attack. Understanding this cylinder's function helps operators effectively manage their equipment and results in improved performance and efficiency in grading tasks.