Purchasing material from a single rolling at a steel mill allows your bender/roller to provide a more consistent and uniform product. Different mills produce steel that, while the same size and shape, may be produced in a different fashion. Even within the same mill, different batches will bend differently due to variations in material composition. Purchasing all your material from the same rolling will allow you to make sure the material is uniform.
If a large quantity of a uniform shape and size of steel is required, it often also makes sense to purchase steel directly from a mill to keep costs low. Direct shipping and bulk ordering are two of the biggest cost saving aspects of purchasing from a mill. There are some contingencies that need to be dealt with, however. A longer lead time is required since the steel needs to be produced. Typically one to two months’ notice is needed, and if it is an unusual grade or size, additional time may be required. Minimum quantities need to be ordered as well. This can vary depending on the size and grade of material, but for shipping reasons, ordering a full truck load (20+ tons) often makes the most sense.