Typical Coefficient of Friction Values for Common Materials

The static and kinetic friction coefficient values reference table shown in this article will be helpful for finding the COF values of commonly used materials.

Static and Kinetic coefficient of friction

Fig.1: Showing the Concept of Coefficient of Friction

Image Source: Wiki

Both the types of COF can be expressed by the same equation as below (refer with the Fig.1):

μ= Ff/N………………Eq.1

Where,

Ff – Frictional force along the surface

N – Normal reaction perpendicular to the surface.

μ – Coefficient of friction between the block and the surface, for Static friction it is termed a μs and for kinetic or sliding friction it is termed as μs or μk .

Then what is the difference between static and kinetic friction coefficient?

For static COF the block must be in static or non-moving condition, i.e., you have to take the friction force value of the force which is applied to the block for giving motion to it but the force value has not yet reached to the limit that can move the block.

For sliding or kinetic friction coefficient, you have to consider the friction force value of the moving block.

Friction Coefficients table

Although, reliable sources (mentioned at the reference section) has been used for compiling the above COF table but still the values shown are approximate only. The friction coefficient value changes not only with material but also with the position and orientation of the participating materials. So, if you need accurate COF value, you must obtain it by experiment only.
Reference

• ASM-VOL 18-FRICTION, LUBRICATION AND WEAR TECHNOLOGY

• Friction Science and Technology FROM CONCEPTS to APPLICATIONS – By Peter J. Blau

Shibashis is a mechanical design engineer by profession and writer/blogger by passion. He has worked in various design projects in automobile, power plant and heavy earth moving equipment domain since 2005.

In his spare time apart from maintaining this blog, he enjoy investing time building his first RC plane

Nothing I could say would give you undue cdreit for this story.

2. Anton

What is the coefficient of static friction between silicon and graphite? thank you.

3. Anton

What is the coefficient of static friction between silicon and graphite? thank you.

4. thamlett

what would be the static and kinetic COF of PTFE impregnated, hardcoated aluminum on the same. I think the specification limit of 0.15 is too low for this application.

5. Nayara

What is the coefficient of static friction between Nylon (Plastic) and Brass? thank you.

6. Milos

How come there is a difference between Steel – Teflon and Teflon – Steel in table above. Or, for example Aluminum – Steel and Steel – Aluminum?

7. hambaAllah

And what about rubber and metal?

8. najeeb

what is coeffient of friction between bitumen and concrete.

9. Ajish K Prakash

static coefficient of friction with nylon and mild steel

12. harsh sarda

What about zirc alloy and steel

13. Jean Clinton

what about ss & plain carbon steel

14. Pramod Patil

Do we have table showing static and kinetic COF for PE fillm, laminate film,and flexible packaging related films.