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The basic pin guide

Paul Gardette

What's a pin for?

A pin is a cylindrical mechanical element (cylindrical pin) with various functions: 

  • Positioning: The pin maintains alignment between two mechanical parts.

  • Secure: The pin secures two parts together and holds them in place.

  • Act as a pivot pin: The pin allows the parts it connects to rotate freely in relation to each other.

  • Secure: The pin protects the elements it joins together, preventing accidental disassembly.

In addition to its main functions, a pin can also be used to : 

  • Transmitting forces: A pin can be used to transmit forces or torques between two parts. 

For example, in braking system applicationthe pin transmits forces between the brake pads and discs, transforming hydraulic pressure into braking force.

  • Aligning parts: A pin can help to align parts during assembly. 

For example, a tapered pin allows the piston to be precisely aligned with the connecting rods. 

  • Isolate vibrations: A pin can reduce noise by absorbing vibrations caused by the mechanism. By perfectly aligning parts, we optimize the transmission of forces, thus reducing vibrations, which are isolated and absorbed by the pin.

The different pin families 

The pin family can be divided into several parts depending on their response to mechanical stress: 

There are 2 main families of mechanical pins: 

  • Fixing pin or clamping pin
  • Positioning pin

What is a clamping pin? 

A clamping pin is a pin whose purpose is to position and assemble two parts relative to each other by compressing, thanks to the pressure exerted on the parts. 

Clamping pins ensure the safety and reliability of the assemblies in which they are used. 

What is a positioning pin?

A positioning pin is used in manufacturing facilities for precise positioning of your parts. 

The positioning pin can be designed specifically for your application to meet your alignment needs. 

Positioning pins and clamping pins are both mechanical pins. mechanical pins and fixing pins.

Different types of pins

Among the standard pins that we can manufacture, there are several types, of which the following are the main ones: 


  • Conical pin
  • Grooved pin
  • mecanindus pin, elastic pin
  • Ground cylindrical pin
  • Cylindrical pin
  • Conical pin with threaded stud
  • Tapped conical pin
  • Threaded pin
  • Split pin

Some examples of pin use

We design different types of pins to meet the fastening and assembly requirements of different industries: 

By car :

  • Pins can be used in brake systems to hold brake pads in place.
  • They are also used in suspension systems to secure shock absorbers and springs.
  • In engines, pins can be used to hold components such as pinions or camshafts in place.

In medicine :

  • Pins are used in medical devices such as oxygen regulator valves.
  • They can also be used in surgical instruments to assemble them securely.

In other sectors :

  • In the manufacturing industry, pins are used in machines and equipment to assemble different parts.
  • In the aerospace industry, pins can be used to assemble aircraft and satellite structures.
  • Pins are also commonly used in furniture and joinery to assemble wooden parts.

How to choose the right pin? 

To choose the right pin for your application, it's essential to consider several criteria. 

Here are the main ones to consider:

Type of mechanical stress: determine the type of stress to which the pin will be subjected (tensile, shear, bending, etc.) and select the pin type best suited to these stresses. 

For example, a cotter pin can be used for shear loads, while a cylindrical pin is more suitable for tensile loads.

Type of fastening: select the type of pin fastening according to application requirements. Common options include the cotter pin, the cylindrical pingrooved splined pinetc.

Diameter and length: choose the pin diameter and length according to the dimensions of the parts to be assembled and the load requirements. Make sure the pin is large enough to support the load without bending or breaking.

Material: select the pin material according to the specific application and environment in which it will be used. At LGC, we design pins in steel, stainless steel, brass, aluminum and other materials on request.

Make sure the material you choose offers the strength and durability your pin needs to withstand the anticipated loads and resist corrosion or other environmental factors.

The tolerance class must also be considered.

Need help making the ideal pin for your application? 

With 85 years' experience in the design and manufacture of custom pins, don't hesitate to contact us for all your fastener and mechanical pin needs, our technical experts will guide you in the best possible way.

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