Frequently Asked Questions about Friction Inserts

How do Friction Inserts work?

Friction Inserts are coated with hard particles. As soon as contact pressure is added to the joint, the hard particles penetrate into the surfaces of both bolted parts This creates a micro-interlock, which prevents the connected surfaces from slipping.

What materials can Friction Inserts be applied on?

Friction Inserts can be applied on to any kind of material, e.g. aluminum, carbon fiber reinforced plastics, steel, etc. There are practically no limitations.

Can you determine the final static friction coefficient in advance?

The achievable friction coefficient always depends on the whole system. Some criteria are:

  • Material combination of the friction joint 
  • Surface hardness of the materials 
  • Contact pressure 
  • Surface roughness 
  • Grain size of the used hard particles 
  • Distribution of hard particles on Friction Inserts 

The final friction coefficient can only be guaranteed after a proper testing of Friction Inserts in the specific connection.

What is the maximum operating temperature for the particles in the joint?

The maximum operational temperature should be < 800°C. For short temporary exposures, the particles can resist up to 1100°C.

Which particle sizes are available?

The standard particle sizes are 10 / 35 / 55 / 85 / 115 µm. Other grain sizes are available upon request.

Do Friction Inserts add any additional tolerance?

The nonwoven layer of Friction Inserts is so thin that it creates no gap between the bolted parts. The particles penetrate completely into both surfaces. If the parts have a different surface hardness, the particles will penetrate deeper into the soft part than into the hard part.

Can hard particles get lost during the application process or when the connection is in use?

Due to the production process, every hard particle is properly adhered to the nonwoven surface. In addition, the cuttings are never made close to the surface dimensions of the part. There is at least a recess of 1 mm from the total available part surface.

What criteria will be considered when selecting and customizing Friction Inserts to meet customers’ needs?

In order to specify the best configuration of Friction Inserts for your needs, we take into account the surface roughness of both parts, the material combination, possible coatings, the applied contact pressure and the required performance.

Should Friction Inserts cover the whole surface of the parts in the joint?

Often it makes sense to apply Friction Inserts only in areas with the highest contact pressure. Because Friction Inserts do not add any tolerances to the parts, the whole application area does not need to be covered. Due to the laser cutting process and a wide variety of possible shapes, we can customize the shape and fit according to the customers’ needs.

Do Friction Inserts provide corrosion protection?

Friction Inserts are made of 100% inert materials and therefore do not have an impact on the corrosion behaviour of your parts. However they do not actively prevent corrosion.

Do the particles have a certain orientation on the nonwoven surface?

The hard particles on Friction Inserts are distributed homogeneously and have no specific orientation.

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