Our expertise

A comprehensive range of solutions
for your projects!

With more than 40 special processes mastered across 3 complementary sites. From surface preparation to final inspection, STI France covers all your requirements.

+40
special processes
+260
customer qualifications
≥95%
on-time deliveries

A DNA 100% focused aerospace and customer

A culture of excellence, driven by aerospace standards and customer commitment.

Non-Destructive
Testing (NDT)

Securing critical aerospace parts through advanced inspection processes that guarantee compliance, traceability and absolute reliability.

Magnetic Particle Inspection

Magnetic Particle Testing reveals surface and near-surface discontinuities in ferromagnetic materials. When the part is subjected to a magnetic field and indicating particles are applied, any defect creates a flux leakage that becomes immediately visible. Particularly suited to detecting manufacturing and grinding cracks as well as inclusions, this inspection is performed under precisely defined conditions relating to the nature and thickness of any coatings present, in accordance with the requirements of aerospace prime contractors.

Penetrant Testing

Penetrant testing is a surface inspection method applicable to any non-porous material, steels, aluminium alloys, composites. A visible or fluorescent penetrant is applied to the part: it seeps into surface-breaking discontinuities and is then revealed by a developer after rinsing. This technique is particularly effective for detecting manufacturing cracks, machining defects and pitting, and is commonly applied before surface treatment or on ground chrome-plated surfaces.

Nital Etch Inspection

Nital etch inspection is a controlled chemical etching method used to reveal any localised overheating caused by abusive machining or grinding, as well as carburising and nitriding defects. It applies exclusively to heat-treated steel parts with a tensile strength (Rm) of 1,240 MPa or above. Carried out on unplated parts, this inspection requires meticulous surface preparation and expert interpretation of the etch indications, in accordance with current aerospace standards.

Rollscan

Rollscan uses the Barkhausen noise phenomenon to detect grinding burn and variations in residual stress on ferromagnetic parts. When a part is locally magnetised, the abrupt movement of magnetic domain walls generates a characteristic electrical signal — Barkhausen noise — whose intensity varies according to the structural condition of the material. Once calibrated, this non-destructive method provides fast, reliable detection of any thermal or mechanical sub-surface anomaly.

Surface treatments &
coatings

Preserving component performance over the long term through surface treatments that meet the most exacting standards in aerospace and precision engineering.

Cadmium plating (Cr(VI) & Cr(III)), zinc-nickel, silver, nickel and copper plating

These electroplated coatings form the core of STI France Group's anti-corrosion expertise on steel and metal alloy parts. Cadmium plating, available with both hexavalent and trivalent chromate passivation to meet evolving REACH regulations, provides the sacrificial protection long recognised in the aerospace industry. Zinc-nickel delivers superior corrosion resistance while remaining compatible with the requirements of major prime contractors. Silver, nickel and copper plating complete the range for specific functional or conductive applications, each carried out to strict specifications and tightly controlled thicknesses.

Passivation, phosphatation, brunissage, Surtec, Alodine

These chemical conversion and surface protection treatments improve corrosion resistance and prepare parts to receive subsequent coatings. Passivation protects stainless steels by reinforcing their natural oxide layer. Manganese phosphating enhances wear resistance and aids lubrication. Chemical blackening gives a characteristic dark finish while providing light protection. Alodine 1200 and SurTec provide chromate conversion coating on aluminium without hexavalent chromium, in compliance with REACH requirements and the aerospace specifications of major prime contractors.

TSA & SAA anodising

Sulfuric-tartaric anodizing (TSA) and sulfuric anodizing (OAS) are aluminum anodizing processes carried out using next-generation equipment. TSA — performed in a mixed sulfuric acid/tartaric acid bath at 35–40°C — produces thin layers ranging from 2 to 7 µm, offering excellent corrosion resistance and compatible with all grades of aluminum alloys and REACH regulations. These processes are qualified by the leading aerospace OEMs.

Decorative plating

Chemical machining &
stripping

Mastering material removal and surface preparation on large components, with a level of precision suited to critical aerospace applications.

High capacity, up to 4.5 m

STI France Group operates high-capacity facilities able to process large structural components, High capacity, up to 4.5 m STI France Group operates high-capacity facilities able to process large structural components up to 4.5 m in length. This exceptional capacity meets the requirements of aerospace prime contractors for structural parts, wing and fuselage elements that cannot be handled on standard lines. Mastering chemical etching cycles across such large surfaces — while guaranteeing uniform material removal and strict compliance with specifications — is a strong point of differentiation for STI Group in this market segment.

From 10 to 1,000 microns

Chemical machining covers a material removal range of 10 to 1,000 microns, offering great flexibility depending on the application. At low thicknesses, the process enables precise thinning of thin structures without deformation or alteration of the material’s mechanical properties — a decisive advantage in aerospace. At greater thicknesses, it allows complex-shaped machining of aluminum or titanium alloy components that are inaccessible to conventional machining techniques. Precise control of the baths ensures repeatability and traceability.

Technical
coatings

Applying technical and decorative coatings of the highest quality to metal and composite parts destined for the most demanding environments.

On metal and composite parts

STI France specializes in the application of systems aerospace paint systems across a wide range of substrates — heat-treated steels, aluminium alloys, titanium and composite materials. As the final stage of the surface treatment process, paint fulfils several functions at once: corrosion protection, abrasion resistance, sealing and visual conformity. With a range of more than 80 qualified paints, our teams master multi-layer systems (surfacer, primer, topcoat), masking management, deposited thickness control, and up to 12 successive operations on composite parts. large-scale paint booths accommodate structural parts of all sizes, in compliance with the specifications of major aerospace prime contractors.

MCAC / Sermetel

MCAC (*Metallic Ceramic Aluminium Coating*) and Sermetel are aluminum- and zinc-based inorganic coatings, designed for aerospace applications requiring both corrosion protection and resistance to high thermal cycles. Particularly suited to components exposed to temperatures ranging from 200°C to 400°C — landing gear, engine components, fasteners, and structural components — these coatings provide a REACH-compliant alternative to traditional cadmium plating. Applied by spraying onto uncoated parts, they ensure superior corrosion resistance without hydrogen embrittlement, in accordance with the specifications of leading aerospace OEMs.

High-end finishing & cosmetic excellence

Operational Excellence

Coordinated technical expertise ensuring performance, compliance and industrial continuity

Additional treatments
co-managed

Coordinating complementary technical processes with qualified partners to deliver a complete, controlled and compliant treatment chain.

Hard chrome plating and grinding

Hard chrome plating is a high-hardness electrolytic chromium coating (up to 1,000 HV), used to improve the wear, friction and corrosion resistance of components subjected to severe mechanical stresses — cylinders, shafts, slideways and transmission shafts. As an essential complementary operation, post-chrome grinding enables final dimensions to be achieved with very tight tolerances and a surface roughness that meets functional requirements. STI France coordinates these two processes with HARTCHROM AG, the parent company of the STI Group based in Switzerland.

Shot peening

Shot peening is a mechanical surface treatment process that introduces residual compressive stresses into the surface layer of metal components, significantly increasing their resistance to fatigue and cracking. Applied to critical components such as turbine blades, landing gear or structural parts, this treatment is performed using rigorously controlled parameters (Almen intensity, coverage rate, shot size). STI France manages the integration of this operation into the overall treatment process, relying on partners certified to the standards of leading aerospace OEMs.

Heat treatment

Heat treatments — quenching, tempering, annealing and stress relieving — are fundamental steps in the manufacturing cycle of aerospace components, directly determining the final mechanical properties of the parts: hardness, ductility and fatigue resistance. Performed before or after surface treatments, they must be perfectly integrated into the overall process to ensure metallurgical consistency throughout. STI France coordinates these operations with qualified heat treatment partners, ensuring continuity of document control, traceability of the applied cycles and compliance with current aerospace standards (EN 9100, NADCAP).

REACH Compliant

We innovate while respecting both your constraints and our environment. Certified processes, full traceability.

Need assistance?

A project, a technical constraint, a set of specifications? Let’s talk about it.

Our industrial sites

3 sites, 3 complementary
strengths

Unique coordination, maximum responsiveness.
Pau · Bayonne · Águeda to meet 100% of your needs.

See our sites

PAU ARUDY

Pyrénées-Atlantiques, France

BAYONNE

Saint Martin de Seignaux, France

AGUEDA

Portugal

A comprehensive range of solutions for your projects!