Frequently Asked Questions about Advanced Solutions for Component Fatigue Life Enhancement
🔧 Our Technologies and Solutions
What is cold expansion?
Cold expansion is a mechanical process that introduces beneficial compressive residual stresses around machined holes. This technique significantly improves fatigue life of metallic structures by reducing the stress intensity factor and slowing crack propagation.
How does the Split Sleeve system work?
The Split Sleeve system involves pulling a tapered mandrel, pre-equipped with a lubricated sleeve, through a hole in aluminum, steel, or titanium. The expendable sleeve reduces mandrel pulling force, ensures proper radial hole expansion, and enables one-sided processing.
What is an Expanded Bushing?
An expanded bushing is a cylindrical sleeve that is installed into a hole by means of cold expansion. The bushing starts as a smaller diameter component that fits into the hole with clearance, then is permanently expanded to create a tight interference fit using a tapered mandrel. This process simultaneously provides:
- Precise fit: High interference between bushing and parent material
- Fatigue enhancement: Beneficial compressive residual stresses around the hole
- Load transfer: Optimal stress distribution for joint performance
- Durability: Long-lasting connection resistant to wear and fretting
The expanded bushing essentially combines the benefits of cold expansion technology with the functionality of a permanent bushing insert, creating a superior fastening solution for aerospace applications.
What are expanded bushings and how do they work?
Expanded bushings (EB) simultaneously coldwork the material around the hole and provide a high interference fit. The bushing is initially placed in the hole as a clearance fit, then using an oversized tapered mandrel, the lubricated bushing is cold expanded into the parent material, creating beneficial compressive residual stresses while achieving a tight interference fit.
What are the main advantages of expanded bushings over conventional installation methods?
Expanded bushings offer several key advantages:
- Improved Fatigue Life: Fatigue life superior to press or shrink fit installations (minimum 3:1 improvement factor)
- One-Sided Operation: Process accomplished within seconds, no access required from both sides
- Corrosion Resistance: Protective coatings are not damaged during installation
- High Torque and Pushout Resistance: Greater resistance to rotation and pushout compared to conventional methods
- Safer and Quicker Installation: No cryogenic fluid required, eliminates dangerous liquid nitrogen handling
- Enhanced Load Transfer: Better stress distribution compared to conventional bushings
What is EB² (Expanded Bonded Bushing)?
EB² is our solution for composite structures. These bushings are coated during manufacturing with a micro-encapsulated adhesive. During installation, the bushing is slipped over a mandrel and cold expanded into the hole, providing both load transfer through interference fit and adhesion.
What is CompDRILL?
CompDrill is our innovative device for multi-material drilling that enables drilling of metallic/composite assemblies without generating delamination on the back face. This technology is approved in the Structural Repair Manual (SRM) for A350 repairs.
🎯 Applications and Industry Sectors
Which sectors does Capaero serve?
CAPAERO serves primarily:
- Aerospace industry (commercial and military aircraft)
- Aircraft maintenance (MRO)
- Space industry (launchers)
- Defense industry
- Production and assembly operations
What types of materials can be treated?
Our solutions apply to:
- Metallic materials: aluminum, steel, titanium, superalloys
- Composite materials: carbon/epoxy, carbon fibers, hybrid metal/composite structures
- Multi-material assemblies: metal/composite combinations
What are the benefits of your solutions?
Our technologies offer:
- Improved fatigue life: minimum 3 to 1 factor improvement
- Small crack growth arrest
- Cost-effective alternative to redesign
- No weight addition to the structure
- Simple one-sided operation
- Applicable in production and renovation
🌍 Partnerships and Distribution
Is Capaero a distributor for other brands?
Yes, Capaero is the exclusive distributor of West Coast Industries (WCI) products in Europe, Africa, Middle East, India, and Russia, including Split Sleeve tooling.
What is West Coast Industries (WCI)?
West Coast Industries is an industrial leader in coldworking tooling, providing quality tools and services worldwide for over 55 years. WCI is the oldest manufacturer of cold expansion tools, having started in 1971.
🔬 Technical Services and Support
What technical services do you offer?
Capaero provides comprehensive support:
- Design and simulation: Finite Element Analysis (FEA) calculations
- Laboratory testing: solution validation
- Engineering support: customer team assistance
- Operator training: equipment installation and use
- Production: manufacturing of bushings and specialized tools
Do you provide training?
Yes, we offer specialized training for:
- Installation and use of our equipment
- Cold expansion techniques
- CompDrill use for composite drilling
- Best practices in aerospace assembly
How can I get technical support?
Contact our technical team:
- Email: customer@capaero.com
- Phone: +33 5 61 92 04 91
- We work closely with aircraft manufacturer teams to support maintenance and production operations
📋 Processes and Quality
What are your quality processes?
Capaero is EN9100 certified, ensuring:
- Compliance with the strictest aerospace requirements
- Complete process and production traceability
- Rigorous quality control
- Continuous improvement
How are your solutions validated?
Our solutions are validated through:
- Fatigue testing in laboratory
- Finite Element Analysis (FEA)
- OEM qualifications (e.g., Airbus, Boeing or SAFRAN)
- Feedback from experience in production and maintenance
Do your products require specific training?
- CompDRILL: light training required, intuitive use
- Split Sleeve: technical training recommended
- EB: installation training mandatory for optimal performance
💼 Orders and Deliveries
How can I order your products?
Contact our sales team:
- Email: customer@capaero.com
- Phone: +33 5 61 92 04 91
We offer complete kits including all necessary elements: tooling, bushings, specific cutting tools, etc.
Do you offer customized solutions?
Yes, we develop tailor-made solutions adapted to our customers’ technical specifications. Our engineering team works closely with your teams to develop optimized solutions.
What is the delivery time?
Lead times vary according to project complexity. Contact us for a detailed quote with delivery schedule adapted to your needs.
🔧 Specific Technical Questions
What is the difference between cold expansion and other surface treatments?
Cold expansion creates compressive residual stresses within the material mass around the hole, unlike surface treatments that only act on the surface. Compressive area is deeper in the material. This provides more durable and effective protection against fatigue.
Does CompDrill work on all types of composites?
Compdrill work with all kind of composite but is optimized for carbon/epoxy composites and hybrid metal/composite assemblies. It prevents delamination even on simple composite plates, without back support plate.
How do I choose the right tooling size?
Our technical team assists you in selecting appropriate tools based on:
- Hole diameter
- Material type
- Assembly thickness
- Specific application constraints
This FAQ covers the main questions related to CAPAERO’s activities. For any specific question not covered, please contact our technical team directly.