Abstract-Whereas the prototypes of the main quadrupoles had been pursued at CEA Saclay under contract with CERN, the contract to build all MQ magnets and the complete cold masses had been placed with ACCEL Instruments GmbH. After careful evaluation of design concepts and fabrication processes some revisions have been introduced to ease an industrial fabrication of the 400 MQ magnets and cold masses to be delivered to CERN. First batches of magnets were successfully cold tested. We report about the upgrading of the fabrication facility including the MQ specific layout of all machinery, the upgrading and qualifying of personnel resources and processes, the technical performance of the products and main activities and experiences on the way to series production.