The UPI steel finishing plant is owned and operated by U.S. Steel Corporation.


UPI is ISO 14001 and 9001 certified.

Please make a selection for the corresponding certificate.

At UPI we embrace change. Our company philosophy celebrates the commitment, agility, speed and vision needed to embrace change head-on and then conquer it. Continual improvement is part of our heritage. Since 1910, UPI has adapted to the varying needs of the marketplace, always with an eye toward better business, better service, and becoming a better partner to our customers.


    Over the next few years UPI has much to celebrate:

    • 20th anniversary
    • Sales exceeding $1.0 Billion
    • The modernization of the DUO Mill
    • 100th anniversary of steel manufacturing in Pittsburg, CA.

    Today, UPI manufactures Cold Rolled Annealed, Cold Rolled Full Hard, Hot Rolled Pickled & Oiled, Hot Dipped Galvanized, and Tin Mill products starting from Hot Rolled steel supplied by our owners. With the support of nearly 700 hourly and salaried employees, UPI ships high quality steel to more than 150 customers throughout North America.

  • 20001990In the mid 90’s UPI was awarded for Outstanding Corporate Environmental Achievement by the National Environmental Development Association and attained ISO 9002 certification, acknowledging our compliance with the highest international standards for quality and manufacturing processes.First long distance bar coding technology developed by and for UPI. Technology that enables the company to identify a coded coil from more than eighty-one feet away also enables us to better track customer orders from beginning to end.The $25 million improvement of our No. 2 continuous coating line is approved; enabling UPI to supply the best galvanized in the West, and improves line productivity by 30,000 tons per year.

    In 2001, UPI suffered a devastating fire to one of its operating facilities – the Tandem Cold Mill (TCM). The TCM was completely destroyed and had to be rebuilt from the ground up. Showing remarkable resiliency, UPI was able to rebuild the TCM in less than nine months, and it now stands as one of the world’s most technologically advanced mills of its kind.

  • 19801970With the advent of new production processes, increased use of alternative materials (like aluminum and plastic), and growing competition from foreign imports, the Pittsburg plant suffered financially. In an effort to improve competitiveness and market share, the facility underwent reorganization. First, excess product lines were dropped so the plant could focus on its two main products: sheet and tin. In addition, in 1986 U.S. Steel entered into a 50/50 joint venture with Pohang Iron and Steel Company. The newly formed partnership engaged in a comprehensive modernization program designed to upgrade the processes and equipment of the facility. UPI is formed.In 1988 the Learning Center opens to promote continuous education. Over 90 courses are now offered to employees and members of the community.The $450 million modernization was completed in 1989, representing one of the largest investments in a manufacturing facility in California during that decade. A new era of world-class operations begins with a consistent supply of continuously cast, high-quality hot bands arriving by ship and rail from the joint venture partners.
  • 19601950U.S. Steel becomes the first manufacturer in the West of galvanized sheet and thin-gauge tinplate. Plant employment peaked at about 5,200 men and women. The plant now covers 1,072 acres with 87 acres under roof. The plants single-sheet feed operations were replaced by more efficient cold rolling mills and continuous feed lines. When a pipe mill was added, the Pittsburg facility gained the distinction of having the most diverse product line of any steel plant in the United States.
  • 19401930During the 1930’s and 1940s, facilities and equipment were added to help supply major public works projects – the most notable being the San Francisco/Oakland Bay Bridge – and to meet the demand for steel products during WWII.Post-war expansion includes modern continuous sheet and tin mills, the West’s first continuous rod mill, cold rolling mills, electrolytic tinning, cleaning, continuous coating and annealing lines.
  • 19201910The first Pittsburg steel facility opened in 1910 as a 60-man foundry under the name of Columbia Steel. Consisting of one building and a single 150-ton open hearth, the plant furnished steel castings for the dredging, lumber and shipping industries.In the 1920’s, the plant expanded to include the West’s first nail mill, and later, the first hot dip tin mill west of the Mississippi.