The following table shows a selection of frequently used values of the coefficients for static friction µ0 (static coefficient) and sliding friction µ (also called friction values).
| static coefficient µ0 dry | lubricated | kinetic friction µ dry | lubricated | |
|---|---|---|---|---|
| Aluminium alloy- Aluminium alloy | 0,15...0,60 | |||
| Brake lining-Steel | 0,50...0,60 | 0,20...0,50 | ||
| Chrome-Chrome | 0,41 | |||
| Copper-Copper | 0,60...0,70 | |||
| Iron-Iron | 1,0 | |||
| Leather sealing-Metal | 0,60 | 0,20 | 0,20...0,25 | 0,12 |
| Nickel-Nickel | 0,39...0,70 | |||
| POM-H - PA6.6 | 0,5 | |||
| POM-H slide modified - PA6.6 slide modified | 0,14 | |||
| POM-H - PE-HD | 0,3 | |||
| POM-H - PE-HD slide modified | 0,15 | |||
| S235JR-S235JR polished | 0,15 | |||
| Steel-Copper | 0,23...0,29 | |||
| Steel-Gray cast iron | 0,18...0,24 | 0,10 | 0,17...0,24 | 0,02...0,21 |
| Steel-Ice | 0,027 | 0,014 | ||
| Steel-Lead | 0,50 | |||
| Steel-PA | 0,32...0,45 | 0,10 | ||
| Steel-PTFE | 0,04...0,22 | |||
| Steel-"S"green | ~0,20 | |||
| Steel-Steel | 0,45...0,80 | 0,10 | 0,40...0,70 | 0,10 |
| Steel-Tin | 0,60 | |||
| Steel-White metal | 0,21 | |||
| Wood-Metal | 0,50...0,65 | 0,10 | 0,20...0,50 | 0,02...0,10 |
| Wood-Wood | 0,40...0,65 | 0,16...0,20 | 0,20...0,40 | 0,04...0,16 |
Explanations of the material names
PA: Polyamid
PE: Polyethylen
POM: Polyoxymethylen
PTFE: Polytetrafluoräthylen or Polytetrafluorethylen
S235JR: Material number 1.0038
"S" green: PE-based plastic, also known as Murtfeldt "S" green, standard material for sliding guides
White metal: Alloys of lead and tin
Here are some engineering mechanics exercises regarding friction.
