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Our processes

For machining, welding and heat treatment of your rings

High-precision manufacturing processes

The Defontaine Group is the historical and reference partner of the precision industry. In order to meet the very high standards of our customers and their needs, we offer a wide range of controlled and customised solutions for the manufacture of rings in small series, large series and prototypes.

 By machining, deformation or fusion processes, the Defontaine Group can help you define the best manufacturing processes according to the constraints your parts must withstand. Our proven expertise and know-how allow us to manufacture and deliver more precise, durable and reliable rings worldwide.

Our machine stock for state-of-the-art technology

  • 5-axis machining centre
  • Automated and robotic machining lines
  • Flexible machining equipment for small and medium series, prototypes.

Defontaine, your expert in special processes

We have developed proven expertise in special processes, to ensure that our products meet the requirements of our customers.

“A special process is a process whereby the resulting output cannot be verified by subsequent monitoring or measurement, and, as a consequence, deficiencies become apparent only after the product is in use.”

Source: NADCAP

A so-called special process is a manufacturing process that is fully controlled by specifically qualified operators and for which the parameters are precisely determined and cannot be changed. The manufacture of a single part may require several special processes. Rollix bearings, for example, are both induction treated and MT inspected.

un employé defontaine applique une peinture verte sur une pièce

Discover all our other skills and trades

Our special processes and their applications

  • Flash-butt welding: Aerospace, automotive industry, industrial bearings
  • TIG welding: Aerospace industry
  • Roller welding: Aerospace industry
  • Conventional and vacuum heat treatment: Aerospace industry, bearings for the wind power, industrial and automotive industry
  • Induction heat treatment: Bearings for the wind power, industrial and automotive industry
  • Press quenching: Industrial applications
  • 5-axis laser cutting: Aerospace industry
  • Electrical discharge machining (EDM): Aerospace industry
  • Metallurgical laboratory: Bearings for the aerospace, wind power and industrial industry
  • Fluorescent penetrant inspection (FPI): Aerospace industry
  • Real-Time X-ray (RTX): Aerospace industry
  • MPI (Magnetic Particle Inspection): Aerospace industry, bearings for the wind power, industrial and automotive industry
  • Ultrasonic Testing (UT): Aerospace industry, bearings for the wind power, industrial and automotive industry

All our special processes are NADCAP certified

machine defontaine pour la rectification de précision
The Defontaine group flash-butt welding process and flash-butt welding, rolling and forging process are a reference in the market. We apply this process to manufacture rough rings from long bars. A low-voltage, high-current flow runs through the previously bent ring and brings both ends to melting temperature, generating bright sparks. Both ends are then forged together, ejecting the excess metal outwards. This high-performance, reliable and economical butt-welding process allows to weld bars and profiles without adding metal, thus reducing your material costs and machining times.
Flash-butt welding

Surface or cylindrical grinding is a finishing machining process that aims to produce high-quality, high-precision metal parts in the micron range.
Grinding of the Rollix ring raceways guarantees the quality of the profile. This precision process also allows Defontaine Group to control the preload applied to our rings. Face and diameter grinding is also possible to reduce runout tolerances for high-precision parts.

The principle of quenching is to heat a material until its internal structure changes and then cool it in a liquid, thus increasing its mechanical strength. To eliminate the deformation caused by this heat treatment, Defontaine Group has developed a technology that guarantees the dimensional conformity of the ring during the heat treatment operation: press hardening. This special process keeps the ring under stress during the hardening phase, thus eliminating any risk of deformation and ensuring uniform hardening.
Press quenching

Induction heat treatment or induction hardening is a non-contact heating system of metals, an electric current is induced in the part. This treatment increases the surface hardness and provides a better resistance to wear and tear against loads. All Rollix ring raceways are induction treated. Internal or external gear can also be treated if necessary.

Induction hardening is an efficient, economical and environment-friendly process which can achieve high hardening depths, process a large number of parts in a short period of time and does not require a vacuum atmosphere or the use of hazardous, polluting or chemical products.

Gear cutting is a machining process used within the Defontaine Group for inner and outer, straight or helical gears for modules 1 to 25. The hobbing profile can be obtained in different ways: individual gear hobbing with a disc cutter, hobbing of the outer gear with a hob cutter or hobbing of a single part with a blade depending on the quality of the gear to be obtained.
Gear cutting

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