In October 1951, Western Electric (Allentown, Pennsylvania plant) began mechanized commercial manufacture of transistors. Until then, since its 1947 invention, the transistor had been manually assembled at Bell Laboratories due to the minuteness of the components and rigid spacing requirements. Allentown mechanized that process, marking the shift from laboratory invention to volume industrial production, yielding transistors of consistent crystalline purity, long service life, and inexpensive reproducibility.