Manufacturing of Aeronautical Pins

Discussing aeronautical pins is not a matter of a simple mechanical element. In the aerospace industry, every structural component is subjected to extreme demands in terms of load, vibration, fatigue and thermal variation. A pin may be small in size, but its impact on the structural safety of an aircraft is critical.

Understanding their design is essential for any professional in the aerospace sector. Knowing what pins are used for in aviation, how they affect structural integrity and what distinguishes a certified component enables sound technical and strategic decisions.

What Are Aeronautical Pins


An aeronautical pin is a cylindrical joining element designed primarily to withstand shear loads (transverse cutting) between two or more structural components.

Unlike screws or bolts, they do not work through threaded friction, but through direct shear resistance.

In aerospace environments, an aerospace pin must meet:

  • Extremely tight dimensional tolerances
  • Full material control and traceability
  • High fatigue resistance
  • Galvanic compatibility with mixed-material structures

When it comes to aeronautical pins, the concept of a “standard industrial part” does not apply. Every component must be designed and manufactured in accordance with specific regulations and certification criteria.


Need help?

Contact our technical office and tell us about your project.

We will study your case and propose a solution to manufacture them.



What Are Pins Used for in Aviation


Understanding what pins are used for in aviation means understanding their structural relevance.

In civil and military aircraft, pins for aeronautical applications fulfil critical functions such as:

1. System Articulation

  • Landing gear (pivots and trunnions)
  • Control surfaces (ailerons, rudder, elevators)
  • Hydraulic actuators

These elements allow controlled movement under load without generating premature wear.

2. Locking and Safety

This is where locking pins and positive safety systems come in, used for:

  • Landing gear locking during maintenance
  • Temporary securing of critical mechanisms
  • Ejection systems in military aviation

Many professionals search specifically for what locking pins are in aeronautics, as their function is to prevent accidental movement under intense vibration.

3. Structural Positioning

In primary structural joints, they eliminate any clearance that could generate fretting or accelerated fatigue.

Types of Pins in the Aeronautical Industry

Different types of pins exist in the aeronautical industry, each optimised for a specific function.

Clevis Pins

  • Allow controlled rotation
  • Combined with safety cotter keys
  • Frequently used in control systems

Cotter Pins

  • Secondary safety element
  • Non-reusable
  • Used with castellated nuts

Quick Release / Ball Lock Pins

  • Retractable ball system
  • Fast installation and removal
  • Very common in ground support equipment and access panels

Taper Pins

  • Zero-clearance fit
  • Ideal for continuous shear loads

Roll / Spring Pins

  • Secondary load applications
  • Limited use in non-critical structural components

Correct type selection depends on load, vibration, accessibility and applicable regulations.

Types of Pins in the Aeronautical Industry<br/>


Materials Used for Aeronautical Pins

The materials used for pins determine their behaviour under load, corrosion and temperature.

17-4 PH Stainless Steel

  • Precipitation hardened
  • High shear resistance
  • Excellent corrosion resistance

Titanium (Ti-6Al-4V)

  • High strength-to-weight ratio
  • Ideal where weight reduction is a priority

Alloy Steel 4130 / 4340

  • High mechanical strength
  • Requires protective coatings

Common Surface Treatments

  • Zinc-nickel plating
  • Passivation
  • Specific heat treatments

Material selection depends on the operating environment, load cycles and regulatory requirements.

Materials Used in the Manufacture of Aeronautical Pins

Applicable Standards and Certifications

Aeronautical pins are governed by strict standards that ensure safety and interchangeability.

AN (Air Force – Navy)

Historical standards still widely used.

MS (Military Standard)

Standardisation from the U.S. Department of Defense.

NAS / NASM (National Aerospace Standards)

Represent a higher level of technical requirement.

MIL-SPEC

Defines specific physical and operational requirements, including vibration testing.

In addition, quality management systems such as AS9100 and full documentary traceability requirements must be considered in Europe.

Manufacturing of Aeronautical Pins: Precision and Cold Forming

The manufacture of aeronautical pins demands advanced industrial processes.

Key requirements include:

  • Dimensional control in microns
  • Controlled heat treatments
  • Non-destructive inspection
  • Repetitive production with zero tolerance

Precision cold forming enables:

  • Efficient high-volume production
  • High dimensional repeatability
  • Optimised material utilisation
  • Cost reduction compared to full machining

For manufacturers, government bodies and the defence sector in Spain, working with specialists in high-precision industrial processes is decisive in guaranteeing safety and competitiveness.

How to Choose an Aeronautical Pin Supplier in Spain

If the objective is to find a manufacturer or industrial partner, these are the key criteria:

  • Experience in the aeronautical or defence sector
  • Knowledge of AN, MS and NAS standards
  • Series production capability
  • Full documentary traceability
  • Certified quality control

Selecting the right supplier is not merely an economic decision. it is a strategic one, essential for ensuring safety and regulatory compliance.

Precision Is Not Optional in the Aeronautical Industry

In aviation, every component fulfils a critical structural function. Aeronautical pins must be designed, selected and manufactured to standards that eliminate any margin for error.

From material selection to series production through processes such as cold forming, every phase directly influences the safety of the complete system. In an environment where traceability and certification are mandatory, working with a specialised such as LEMEC makes the difference between an industrial part and a certified aeronautical component.

Get in touch with us

Contact our technical office and tell us what kind of steel parts you need to manufacture.

We will study your case and propose a customized, fast and efficient cold stamping solution.

Preguntas frecuentes sobre pasadores aeronáuticos

¿Qué tolerancias dimensionales suelen exigirse en pasadores aeronáuticos?

En aplicaciones estructurales críticas, las tolerancias pueden situarse en rangos de micras, dependiendo del tipo de ajuste (interferencia, transición o con juego). Una desviación mínima puede generar vibraciones, desgaste por fretting o pérdida de alineación, afectando a la vida útil del conjunto.

¿Qué ensayos se realizan antes de aprobar un lote de pasadores aeronáuticos?

Además del control dimensional, suelen realizarse ensayos de dureza, análisis metalográfico, verificación de tratamientos térmicos y pruebas no destructivas como líquidos penetrantes o partículas magnéticas. En aplicaciones críticas también pueden exigirse validaciones de primer artículo (FAI).

¿Cómo influye la fatiga en la vida útil de un pasador aeronáutico?

Los pasadores trabajan frecuentemente bajo cargas cíclicas. Con el tiempo, estas cargas pueden generar microfisuras que evolucionan hasta una fractura por fatiga. Por ello, el acabado superficial, el tratamiento térmico y el diseño geométrico son determinantes para aumentar su durabilidad.

¿Qué diferencia hay entre un pasador estructural y uno de mantenimiento?

Un pasador estructural forma parte permanente del sistema y soporta cargas operativas durante el vuelo. En cambio, un pasador de mantenimiento se utiliza temporalmente para bloquear mecanismos durante inspecciones o intervenciones técnicas.

¿Es mejor fabricar pasadores aeronáuticos mediante mecanizado o estampación en frío?

Depende del volumen y del diseño. El mecanizado puede ser adecuado para series cortas o geometrías complejas, mientras que la estampación en frío ofrece mayor eficiencia y repetibilidad en producción masiva, optimizando costes sin comprometer precisión cuando el proceso está correctamente controlado.

¿Dónde encontrar un proveedor especializado en pasadores aeronáuticos?

Para proyectos que exijan precisión dimensional, trazabilidad completa y capacidad de fabricación en serie, es recomendable acudir a un fabricante industrial con experiencia en procesos como la estampación en frío y conocimiento de normativas aeronáuticas. Trabajar con un proveedor especializado garantiza cumplimiento técnico y fiabilidad a largo plazo.

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