Section 1031 allows a good deal of flexibility for equipment in these categories. Most construction machinery, or “yellow iron” as it’s known in the industry, falls within NAICS code #333120. The same goes for farming machinery and implements, within NAICS #333111. Companies and individuals looking to replace or upgrade equipment in either of these categories can use proceeds from one or more types of equipment to obtain a different type of equipment. Examples: relinquish a bulldozer and a grader and replace into an excavator and a crane; or relinquish a combine and a farm tractor and replace into an irrigation system.