What tool is essential for achieving accurate corners in cabinetry installation?

Using a square is essential for achieving accurate corners in cabinetry installation due to its ability to ensure that angles are precisely 90 degrees. When installing cabinets, it is vital that both the frames and the individual cabinet pieces are aligned correctly to create a seamless appearance and to ensure that doors and drawers operate properly. A square allows the carpenter to check the squareness of both horizontal and vertical surfaces, helping to prevent issues such as gaps, misalignment, or improper fitment that could arise later in the installation process.

While a level is important for ensuring that surfaces are even and a measuring tape is useful for obtaining accurate dimensions, neither tool directly addresses the crucial requirement for right angles. Additionally, although a drill is necessary for fastening components together, it does not assist with verifying or achieving square corners. Hence, a square stands out as the critical tool in this context for ensuring precise corner installations in cabinetry.