Precision engineered washers and stamped components GRIS

Engineering background and manufacturing facilities of GRIS Group

The engineering background of French industrial group GRIS originated in 1984 through the foundation of Gris Découpage by Francis Gris.

Over four decades of steady technical investment, the independent family enterprise grew into a respected European developer of high-speed precision stamping, metal blanking, and engineered technical washers.

The operational layout combines the main production facility in Lesménils, France, with the specialized branch Gris Umformtechnik in Hersdorf, Germany.

Group manufacturing complexes house high-speed stamping presses, robotic Swiss modular tooling lines, and heat treatment furnaces.

The management framework conforms to demanding automotive specifications IATF 16949, alongside ISO 9001:2015, ISO 14001:2015, and the premier TISAX (AL3) assessment level. Engineering departments design stamping tooling using Solidworks, Logopress, and COLDFORM simulation software.

Precision engineered washers for demanding industrial joints

The precision engineered washer line from GRIS fulfills challenging joint assembly requirements in vehicle production, railway rolling stock, energy infrastructure, and heavy mechanical machinery.

Unlike ordinary commercial hardware rings, GRIS precision washers are manufactured with thickness and flatness tolerances verified down to micrometers. The portfolio includes oversized flat washers, conical spring discs, spherical seating elements, and intricate blanked profiles.

Deploying precision conical and dished spring washers delivers uniform distribution of mechanical clamping loads beneath bolt heads and hex nuts, eliminating localized yielding on mating parts.

The calculated elastic deflection compensates for differential thermal movement between dissimilar structural metals and absorbs tension relaxation, ensuring steady preload retention across the full working life of the joint.

Exclusive anti-loosening spring washer system GRIS TREP

The patented anti-vibration system TREP represents a proprietary development by GRIS engineered to prevent threaded fasteners from vibration loosening under severe cyclic loads.

Mechanically, the unit features a pre-assembled stack of three or four smooth conical spring washers calibrated for deflection loads and permanently linked via an internal metal sleeve. This configuration prevents field assembly errors and provides smooth progressive spring stiffness.

Unlike conventional spring washers, the TREP system compensates for permanent settling and material creep within assembled components, maintaining positive retention force across decades of operational duty.

For installations involving softer metals (such as aluminum alloy housings), a dedicated TREP model includes an integrated wide flat base washer, eliminating rotational surface gouging and protecting structural seating surfaces.

Wedge-locking safety washers series Gris Lock for severe vibration

The Gris Lock wedge-locking washer series employs a cam-wedge mechanical principle to safeguard threaded joints subjected to dynamic vibration and mechanical shock. Each pair consists of two matching washers featuring internal inclined cam ramps and external radial grip ribs.

The ramp angle on the internal cam surfaces exceeds the lead angle of metric and unified bolt threads, providing positive mechanical lock-up when fasteners attempt to loosen.

During severe vibrational excitation, external friction ribs bite into the bolt bearing face and structural mounting surface.

Any rotary unthreading motion forces the washers to slip along their internal cam ramps: because the cam incline is steeper than the fastener thread, this relative movement generates an axial extension that raises bolt tension and prevents further back-off.

Gris Lock washers are fabricated from hardened steel and stainless alloys.

Diamond-coated friction shims for high-torque mechanical joints

Advanced diamond-coated friction shims from GRIS provide a high-technology method for multiplying load capacity across precision flanges and shaft-to-hub interfaces. A resilient thin steel core is coated with microscopic synthetic diamond particles of controlled grit sizing.

When mounting bolts are torqued down, the ultra-hard diamond crystals embed into the surface microstructure of both adjoining metal components.

This micro-scale interlocking multiplies the static coefficient of friction across the joint by three to four times relative to ordinary dry ground surfaces.

Consequently, machinery can transmit significantly greater torsional drive moments within compact envelope dimensions, eliminating micro-slip motion, fretting corrosion, and fatigue crack formation without enlarging shaft diameters or relying on heavy keyway milling.

Precision blanked mechanism parts and industrial sealing caps

The precision components division at GRIS produces a broad variety of blanked and formed metal parts with complex contours for vehicle powertrains, industrial transmissions, fluid pumps, and hydraulic distribution blocks.

Implementing Swiss modular tooling delivers concentric holes, counterbores, and intricate openings with tolerances tighter than five micrometers, eliminating the need for subsequent machining or face grinding operations.

Another core product branch involves industrial sealing plugs and cup plugs engineered in accordance with German manufacturing standards DIN 443 and DIN 444 (types A and B).

Formed from carbon steel or stainless alloys, these sealing caps are driven with an interference fit into lubrication passages and cooling fluid galleries within engine blocks and hydraulic manifolds, ensuring positive hermetic sealing under elevated operating fluid pressures.