Allow Stephens MFG to supply your successful business building blocks. Concrete Industry Segments Ready Mix Precast Central Mix RCC Environmental Material Handling The Stephens Process Bill Stephens began Stephens Manufacturing in 1957. Stephens Manufacturing is one of the largest global manufacturing of concrete plants in the world, shipping batch plants all over the world. Stephens Manufacturing is still owned and operated by the Stephens family. Learn More About Stephens Manufacturing Stephens equipment is designed and fabricated to meet specific seismic requirements for the location the equipment will be erected in.