| Material | non-lubricated | lubricated | 
| steel - steel | 0.8 | 0.16 | 
| steel - cast iron | 0.4 | 0.21 | 
| steel - brass | 0.35 | 0.19 | 
| steel - brass | 0.13 | 0.16 | 
| cast iron - cast iron | 1 | 0.15 - 0.20 | 
| cast iron - bronze | 0.25 | 0.08 | 
| bronze - bronze | 0.25 | 0.10 | 
| aluminum - aluminum | 1.35 | 0.30 | 
| copper - copper | 1 | 0.08 | 
| steel - plexiglas | 0.4 - 0.5 | 0.4 - 0.5 | 
| plexiglas - plexiglas | 0.8 | 0.8 |