A pipe frame or green frame unit is a kit for the pipe frame or green frame that provides a set containing all the parts required for constructing the unit. In many cases, the pipe frame or green frame is assembled simply by tightening the bolts of joints assembled to the frame materials. Most unit type products are self-assembly types. Unit variations include those for making platform trucks, partitions, work benches and racks. Casters can be mounted to some products, while in others, the number of shelves can be customized flexibly.