The forerunner of Oil City Iron Works, Inc. was established in 1866 on its present site as a small machine shop and foundry. The early products of the company consisted primarily of parts for cotton gins, brick presses and castings for the building industry. The company was renamed to Oil City Iron Works, Inc. at the turn of the century when the area was in the midst of the oil boom. The company reoriented its operation toward providing castings for the oil industry. By 1960, Oil City Iron Works, Inc. had become a pioneer in this area introducing and developing certain applications for ductile iron.
Since 1985, Oil City Iron Works has expanded significantly and has diversified its products into lines such as valves, pumps, power generation, gas turbine and compression parts, mining equipment, as well as general oilfield equipment. Oil City Iron Works, Inc. is a 100% jobbing shop all "Made in the USA" with over 7,000 active patterns.