From their website:
You can depend on Maruichi American Corporation (MAC) to meet your needs for delivery of quality ERW steel tubing and pipe. Maruichi American Corporation began production in 1980 with three tube and pipe mills and a slitting line to provide a superior domestic product for our customers.
Since then, we have expanded to six mills and two slitting lines which provide a range of round products from 5/8′ to 12′ and square and rectangular tubing to 10′ x 10′ x 0.500′ x 60′.
As the largest structural and ornamental tube mill on the west coast, Maruichi American Corporation (MAC) is committed to providing the best service to our customers. Maruichi Steel Tube Ltd. and its group companies are world leaders in the welded tube industry, having offered customers dedicated services through tubemaking since our establishment in 1947.