During its first 30 years, ESCO was mainly a regional supplier of cast steel alloy products for the logging, construction, and pulp and paper industry throughout the Pacific Northwest.

During the 1940s, ESCO added new products to meet demand for supply valves, pump bodies, anchor chains and other components for warships and tanks.

On April 19, 2018, ESCO entered into an agreement to be acquired by The Weir Group PLC, one of the world’s leading engineering businesses, for an enterprise value of $1.285 billion.

[6] Commencing in 2013, ESCO has closed multiple manufacturing and service facilities in recent years, citing a protracted downturn and declining customer demand for their products.

[13] In 2014, the Wall Street Journal reported that ESCO Corporation agreed to pay a $2.1 Million fine for violating U.S. sanctions imposed on Cuba.

[14] In the official penalty notice, the U.S. Treasury Department concluded that ESCO acted with "reckless disregard" and "caused significant harm" to the U.S. sanctions program on Cuba by conducting large-volume and high-value transactions in products made from Cuban-origin nickel, "which were ultimately sourced" from people on the U.S.

[15][16] In November 2011 ESCO and Portland neighborhood representatives signed a Good Neighbor Agreement, which includes an implementation schedule for 17 emission reduction projects over five years.