Production of high precision
mechanical parts



GEMMA used to be part of the SICN Group created in 1957, specialized in the manufacturing of fuel components for graphite gas power stations - SICN’s customers were companies belonging to the nuclear sphere.

  • SICN was acquired by COGEMA in 1985. The discontinuation of the graphite gas power plants forced SICN to find new markets in the military and aeronautics industries.
  • GEMMA , a subsidiary of AREVA, was re-incorporated as an independent company on January 1st, 2002 and entirely took over the mechanical activities of SICN.
  • In November 2004 :
    Franck NAGY, Hervé CASTELLANET and Philippe AUBERT took over the company.


  • Various machining techniques (Turning, milling, graphite parts, Electrical discharge machining, TIG and braze welding , grinding, …)
  • Numerous special processes (Welding, Surface coating by plasma and HVOF projection) and non destructive inspection (Nital/acid etch, magnetic particle inspection, penetrant testing inspection, …); metallography

Because of these diverse capabilities, GEMMA is a High Technology Integrated Manufacturer whose expertise is complementary to SOROME’s know-how within the HITIM Group.

Moreover GEMMA has developed a unit dedicated to High Quality Synthesis Quartz production for customers in the telecommunication, space and military sectors.

Our Customers