Coefficients of Friction 

  Materials                                          Static              Kinetic 
  Steel on Steel                                     0.74                0.57
  Aluminium on Steel                                 0.61                0.47
  Copper on Steel                                    0.53                0.36
  Brass on Steel                                     0.51                0.44
  Zinc on Cast Iron                                  0.85                0.21
  Copper on Cast Iron                                1.05                0.29
  Glass on Glass                                     0.94                0.40
  Copper on Glass                                    0.68                0.53
  Teflon on Teflon                                   0.04                0.04
  Teflon on Steel                                    0.04                0.04
  Steel on Air                                       0.001               0.001
  Steel on Ice                                       0.03
  Tendon and Sheath                                  0.013
  Lubricated Bone Joint                              0.003