The smallest trade size EMT available that can be installed between two big pull boxes is?

In the context of electrical installations, the smallest trade size of Electrical Metallic Tubing (EMT) that is commonly recognized is primarily dictated by standards set by the National Electrical Code (NEC). When considering installations, especially between pull boxes, it’s essential to ensure that the conduit is large enough to allow for the proper pulling of wires without damaging them and to meet the minimum requirements for wire fill.

The 1/2-inch EMT is established as the smallest practical trade size. This size allows for sufficient space to accommodate the conductors while still providing ease of installation, making it a favored choice for many electrical applications. Choosing a conduit that is too small may hinder wire management and negatively impact the installation's compliance with safety standards.

Thus, the answer identifies that a 1/2-inch trade size EMT is adequately sized for installation in the described scenario, ensuring compliance and proper wire management between pull boxes in residential or commercial projects.