For over thirty years, Précision Stéphanoise Industrie has been cultivating its spirit of innovation and developing a renowned know-how focusing on high-precision mechanics: production tools, checking fixtures, and machining and milling to the nearest micron.


PSI designs and produces tools for industry and manufactures precision and high precision mechanical parts according to drawings.

Our different fields of expertise enable us to make a global offer, directly integrating our customers’ production processes:  checking fixtures, production tools, milling, design and repair, 5-axis machining, high precision mechanics, and special purpose machinery.


An excellent know-how based on renowned skills and experience, and state-of-the-art and high-performance production equipment.

Offering top-quality work, being proactive in the production of complex parts by controlling material deformation, working to the nearest micron, respecting surface quality … PSI focuses on excellence to meet its customers’ requirements at all times.

Skills and experience

Created in 1972 in Saint-Etienne (Loire, France), the company is managed by Jacques Patras and has twenty staff - qualified and experienced technicians with an average of 15 years' seniority in the business.

Our work requires diligence and precision and we ensure consistent quality in the parts, subassemblies and special machines that we deliver to our clients.

We hold the following certificates and accreditations:
  • ISO 9001 V2008 Certification for the design and manufacture of precision and high-precision mechanical parts
  • An 'A' rating with the world's top two automobile equipment suppliers,
  • An AREVA accreditation for the manufacture of test pieces for reactor vessels in nuclear power plants.

State-of-the-art and high-performance production equipment

Innovation relies on investment in effective machinery: every year, PSI reinvests 10 to 15% its turnover in new equipment.

The manufacture of complex, high-precision mechanical parts has led us to invest in some of the highest performing 5-axis CNC machines on the market, and also in grinding machines, EDM etc.

In order to meet our clients' precision and inspection requirements, we have set up a metrology lab and extremely effective inspection methods (see Machinery /Inspections Methods page).


If PSI has seen a growth of 20% each year, with a revenue around 2 million Euros (10% of that in exports), it is not only thanks to its ability to provide fresh answers to new projects, but also to the loyalty of its 200 customers.

The extremely high level of skill offered by PSI enables us to work with highly demanding industries: automotive, aeronautics, opticsnuclear, military, medical

PSI works directly for large national and international groups (American, German, Japanese).


Set up in the heart of the Loire region, home of centers of expertise in mechanics, optics, and design, PRÉCISION STÉPHANOISE INDUSTRIE knows how to work within a network to develop or complete its know-how and offer a complete package. Jacques Patras is notably the Chairman of Mecaloire. (see partners page).