Steel modular construction is the use of steel to build a structure that can be disassembled and re-assembled at another location. The process usually starts with a design phase, where engineers calculate the load capacity for each piece of steel in the project. Once this has been done, workers cut each piece from a roll of flat steel to create all necessary components for assembling and connecting them together. After assembly, if necessary it can be welded or bolted together. Finally the entire structure is wrapped in metal armor panels before being erected on site so no stray bolts are visible anywhere else once assembled as some larger buildings may require thousands or tens of thousands of bolts per panel mounted with almost invisible edges on every edge over hundreds and hundreds or millions square feet..