What stake would be used to form a square to round?

To form a square to round transition in HVAC sheet metal work, using the hatchet is the appropriate choice. A hatchet is a versatile hand tool specifically designed for making accurate cuts and angles, which is essential when shifting from a square duct shape to a round duct shape. The hatchet enables the technician to create clean edges and precise dimensions necessary for proper fitting and sealing, which is critical in HVAC applications to ensure efficient airflow and minimize leakage.

This method is typically employed when you have to fit a round duct onto a square opening or connect two different duct shapes. The proper use of a hatchet allows for effective shaping of the metal, ensuring that the transition is smooth and that the components align perfectly together. This is fundamental in maintaining the integrity of the duct system as it enhances the overall performance and effectiveness of the HVAC installation.