Mastering materials to go further

THERMILYON Group specializes in heat treatment and vacuum coatings for mechanical engineering.

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Improve the mechanical performance of your parts

A true pioneer in contract heat treatment for the subcontracting industries, the THERMILYON group has been capitalizing on technical innovation and service provision in heat treatment and vacuum deposition since 1960.

With a network of 9 sites in France and abroad, the THERMILYON Group favors close relationships with its partners and active listening to understand their needs and challenges.

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Solutions tailored to your needs

To ensure that our advice is always well-informed and objective, the THERMILYON Group offers a wide range of solutions to provide treatment adapted to the environment and constraints of the room.

Heat treatment
Heat treatment
parts partially coated with platin vacuum coating
Vacuum deposition
Vacuum deposition
1960

Year the THERMI-LYON Group was founded

5000

More than 5,000 customers in France and abroad

32

Millions of euros in sales

20

Millions of euros in human and technological investment over the past 4 years

165

employees

100

100% of our sites are certified

expertise in every market

To meet the expectations and requirements of certain markets, our sites are specialized and organized by market sector.

Our partners

fim logo
logo uimm auvergne rhone alpes
logo of A3TS, the association for heat treatment and surface treatment
logo cluster aeronautique auvergne rhone alpes
logo cluster aeronautique aerospace valley
logo member of the Astech cluster
woman looking through a microscope
loading a nitrex nitriding furnace at Thermi-Picardie

    Our locations near you

    Trempelec
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    Thermi-Loire
    • 143 Avenue Benoît Fourneyron 42160 ANDRéZIEUX-BOUTHéON
    • +33477555230
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    Thermi-Garonne
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    Thermi-Bugey
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    Infra-Therm
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    Thermi-Picardie
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    Thermi-Metalurgica
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    Thermi-Lyon
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    Thermi-Platin
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    Our certifications

    ISO 13485
    ISO 13485 certification logo

    ISO 13485 establishes the criteria for the quality management system of an organization providing medical devices and related services in compliance with customer requirements and applicable regulations.

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    ISO EN 9100

    EN 9100 certification guarantees the quality management system requirements of the ISO 9001 series, and specifies additional definitions and notes for the aerospace and defense industry.

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    IATF 16949
    logo IATF 16949 certification dedicated to the automotive industry

    The IATF 16949 standard, dedicated to the automotive sector, establishes criteria for quality management processes, encouraging continuous improvement, defect prevention and the reduction of non-conformities and scrap within the automotive supply chain.

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    NADCAP Heat Treating
    logo nadcap heat treating

    NADCAP is an accreditation program for aerospace and defense subcontractors, designed to ensure the quality and reliability of products and services. This accreditation focuses on the special processes employed in the manufacture, testing and maintenance of components and systems used in these industries. Within the THERMILYON Group, NADCAP applies only to the special heat treatment process.

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    ISO 9001

    The ISO 9001 standard, widely recognized throughout the world, helps organizations improve their performance by meeting quality management system requirements and demonstrating a commitment to customer satisfaction.

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    See all our certifications
    Customer testimonials

    Cédric Lancieux

    Technical Director, Euroteknika 

    "We needed to call on a company skilled in vacuum coating to ensure lasting quality for our products. It was thequality aspect that drew me back to them. We make products that stay in patients' mouths; quality is paramount in our business, and it's an aspect that Thermi-Platin more than lived up to. What Euroteknika needs is to differentiate itself in the market, and the coating produced by Thermi-Platin is a differentiator. Today, they are even proactive and solution-oriented. They come to us with real answers."

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    Portrait of Cédric Lancieux, Euroteknika employee

    Claude Madelmont

    Borg Warner Supplier Selection Manager

    "We specialize in what's known as the powertrain; that's everything to do with the engine and transmission. These parts have electromagnetic and wear-resistance characteristics. This is a very important point. The THERMILYON Group specializes in controlled atmosphere nitrocarburizing. This involves heat-treating the part to make it harder and more resistant to wear. This is a state-of-the-art treatment. Trempelec processes 15,000 to 25,000 partsat a time".

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    Portrait of Claude Madelmont, Borgwarner collaborator

    Damien Pignol

    Methods and Supply Chain Engineer at Lisi Aerospace Additive Manufacturing

    "When it comes to research and development aimed at creating new treatments to meet emerging challenges, Thermi-Garonne clearly stands out for its receptiveness and ability to propose innovative solutions, setting itself apart from the competition.
    Thermi-Garonne's uniqueness lies in its 100% management of LISI Aerospace Additive Manufacturing parts."
    As for the service offered by Thermi-Garonne, Damien Pignol expresses great satisfaction, ranking them among the top three suppliers for the company.

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    lisi aerospace logo

    Jérôme Lefebvre

    Purchasing manager at ERMO-tech

    "We specialize in the cosmetics, pharmaceuticals, medical and fine wall sectors, as well as in high-precision, high-speed closures. Thermi-Platin treats certain parts of our molds to extend their service life. All contact, friction and sliding between parts need to be hardened with DLC, a surface coating. Today, we have an average lead time of 3 days with Thermi-Platin. Thermi-Platin has been able to offer relevant products and prove its responsiveness to the needs of the ERMO group. They also provide us with a partner and technical support in our search for solutions.

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      Increase the performance of your parts

      The THERMILYON Group is your partner for improving your mechanical parts. Our teams will help you choose the treatment best suited to your needs.

      Contact us

      Our latest news

      Find out all the latest news about the THERMILYON Group as well as heat treatment and vacuum deposition.

      aeronautical supply chain challenges in île-de-france
      The challenges of the aeronautical supply chain in the Paris Region
      Aeronautics is one of the world's most demanding sectors, and the Paris Region is one of its most dynamic industrial hubs. At the crossroads of innovation, precision and performance, the region's aeronautical supply chain plays a key role in the competitiveness of the French industry. To meet the needs of manufacturers [...]
      April 15, 2025
      The challenges of the aeronautical supply chain in the Paris Region
      Electric car being charged
      Mechanical components of an electric car
      Electric cars have profoundly transformed the automotive industry by rethinking traditional mechanical principles. Unlike internal combustion vehicles, which rely on a combustion engine, these vehicles run on an electric motor powered by a battery. This change has led to a major evolution in the design of mechanical components, which must be adapted to the new [...]
      March 4, 2025
      Mechanical components of an electric car
      aged steel tube
      What does alloy ageing involve?
      Alloy ageing is a widespread phenomenon in the metallurgical industry. Whether used in the aeronautics, automotive or other high-tech sectors, metal alloys evolve over time under the effect of various factors such as temperature, mechanical stress and the environment in which they are exposed. This transformation can be beneficial to the [...]
      March 4, 2025
      What does alloy ageing involve?
      press-hardened part
      Focus on press hardening and its advantages
      Press-hardening serves a very specific purpose: to prevent part deformation during the rapid cooling phase induced by quenching. This method improves the performance of steels by giving them a martensitic structure, without the need for reworking. Designed for large production runs of parts with complex geometries, [...]
      January 30, 2025
      Focus on press hardening and its advantages
      martensitic-hardened metal parts
      Focus on martensitic hardening and its advantages
      The aim of martensitic hardening is to bring out a specific constituent in steels, called martensite, to make them harder and more resistant to wear and mechanical stress. It is one of the oldest known heat treatments of metals, and is still used today, thanks to its effectiveness and the [...].
      January 30, 2025
      Focus on martensitic hardening and its advantages
      heat-treated stainless steel tanks
      Thermochemical treatments for austenitic stainless steels
      Stainless steels are metals renowned for their anti-corrosion properties. Since its creation, THERMI-LYON has been offering its customers a range of thermochemical treatment solutions for austenitic stainless steels on a subcontracting basis. Over 60 years' experience in the treatment of stainless steels [...]
      December 19, 2024
      Thermochemical treatments for austenitic stainless steels