CoefficientOfFrictionChart.pdf
| Coefficient of Friction | |||
| Extreme care is needed in using friction coefficients. Please use additional independent references. For any specific application the ideal method of determining the coefficient of friction is by trials. A short table is included above the main table to illustrate how the coefficient of friction is affected by surface films. When a metal surface is perfectly clean in a vacuum, the friction is much higher than the normal accepted value and seizure can easily occur. | |||
| Effect of Oxide film, Sulfide film on Coefficient of Static Friction | |||
| MATERIAL | Clean & Dry | Thick Oxide Film | Sulfide Film |
| Steel-Steel | 0.78 | 0.27 | 0.39 |
| Copper-Copper | 1.21 | 0.76 | 0.74 |
| Coefficient of Friction | |||||
| Mat. 1 | Mat 2. | Dry | Greasy | ||
| Static | Sliding | Static | Sliding | ||
| Aluminum | Alluminum | 1.05-1.35 | 1.4 | 0.3 | |
| Aluminum | Mild Steel | 0.61 | 0.47 | ||
| Brake Material | Cast Iron | 0.4 | |||
| Brake Material | Cast Iron (Wet) | 0.2 | |||
| Brass | Cast Iron | 0.3 | |||
| Brick | Wood | 0.6 | |||
| Bronze | Cast Iron | 0.22 | |||
| Bronze | Steel | 0.16 | |||
| Cadmium | Cadmium | 0.5 | 0.05 | ||
| Cadmium | Mild Steel | 0.46 | |||
| Cast Iron | Cast Iron | 1.1 | 0.15 | 0.07 | |
| Cast Iron | Oak | 0.49 | 0.075 | ||
| Chromium | Chromium | 0.41 | 0.34 | ||
| Copper | Cast Iron | 1.05 | 0.29 | ||
| Copper | Copper | 1.0 | 0.08 | ||
| Copper | Mild Steel | 0.53 | 0.36 | 0.18 | |
| Copper-Lead Alloy | Steel | 0.22 | |||
| Diamond | Diamond | 0.1 | 0.05-0.1 | ||
| Diamond | Metal | 0.1-0.15 | 0.1 | ||
| Glass | Glass | 0.9-1.0 | 0.4 | 0.1-0.6 | 0.09-0.12 |
| Glass | Metal | 0.5-0.7 | 0.2-0.3 | ||
| Glass | Nickel | 0.78 | 0.56 | ||
| Graphite | Graphite | 0.1 | 0.1 | ||
| Graphite | Steel | 0.1 | 0.1 | ||
| Graphite (In vacuum) | Graphite (In vacuum) | 0.5-0.8 | |||
| Hard Carbon | Hard Carbon | 0.16 | 0.12-0.14 | ||
| Hard Carbon | Steel | 0.14 | 0.11-0.14 | ||
| Iron | Iron | 1.0 | 0.15-0.2 | ||
| Lead | Cast Iron | 0.43 | |||
| Leather | Wood | 0.3-0.4 | |||
| Leather | Metal (Clean) | 0.6 | 0.2 | ||
| Leather | Metal (Wet) | 0.4 | |||
| Leather | Oak (Parallel grain) | 0.61 | 0.52 | ||
| Magnesium | Magnesium | 0.6 | 0.08 | ||
| Nickel | Nickel | 0.7-1.1 | 0.53 | 0.28 | 0.12 |
| Nickel | Mild Steel | 0.64 | 0.178 | ||
| Nylon | Nylon | 0.15-0.25 | |||
| Oak | Oak (Parallel grain) | 0.62 | 0.48 | ||
| Oak | Oak (cross grain) | 0.54 | 0.32 | 0.072 | |
| Platinum | Platinum | 1.2 | 0.25 | ||
| Plexiglas | Plexiglas | 0.8 | 0.8 | ||
| Plexiglas | Steel | 0.4 – 0.5 | 0.4 – 0.5 | ||
| Polystyrene | Polystyrene | 0.5 | 0.5 | ||
| Polystyrene | Steel | 0.3-0.35 | 0.3-0.35 | ||
| Polythene | Steel | 0.2 | 0.2 | ||
| Rubber | Asphalt (Dry) | 0.5-0.8 | |||
| Rubber | Asphalt (Wet) | 0.25-0.0.75 | |||
| Rubber | Concrete (Dry) | 0.6-0.85 | |||
| Rubber | Concrete (Wet) | 0.45-0.75 | |||
| Saphire | Saphire | 0.2 | 0.2 | ||
| Silver | Silver | 1.4 | 0.55 | ||
| Sintered Bronze | Steel | 0.13 | |||
| Solids | Rubber | 1.0-4.0 | |||
| Steel | Aluminium Bros | 0.45 | |||
| Steel | Brass | 0.35 | 0.19 | ||
| Steel (Mild) | Brass | 0.51 | 0.44 | ||
| Steel (Mild) | Cast Iron | 0.23 | 0.183 | 0.133 | |
| Steel | Cast Iron | 0.4 | 0.21 | ||
| Steel | Copper Lead Alloy | 0.22 | 0.16 | 0.145 | |
| Steel (Hard) | Graphite | 0.21 | 0.09 | ||
| Steel | Graphite | 0.1 | 0.1 | ||
| Steel (Mild) | Lead | 0.95 | 0.95 | 0.5 | 0.3 |
| Steel (Mild) | Phos Bros | 0.34 | 0.173 | ||
| Steel | Phos Bros | 0.35 | |||
| Steel (Hard) | Polythened | 0.2 | 0.2 | ||
| Steel (Hard) | Polystyrene | 0.3-0.35 | 0.3-0.35 | ||
| Steel (Mild) | Steel (Mild) | 0.74 | 0.57 | 0.09-0.19 | |
| Steel (Hard) | Steel (Hard) | 0.78 | 0.42 | 0.05-0.11 | 0.029-.12 |
| Steel | Zinc (Plated on steel) | 0.5 | 0.45 | ||
| Teflon | Steel | 0.04 | 0.04 | 0.04 | |
| Teflon | Teflon | 0.04 | 0.04 | 0.04 | |
| Tin | Cast Iron | .32 | |||
| Tungsten Carbide | Tungsten Carbide | 0.2-0.25 | 0.12 | ||
| Tungsten Carbide | Steel | 0.4-0.6 | 0.08-0.2 | ||
| Tungsten Carbide | Copper | 0.35 | |||
| Tungsten Carbide | Iron | 0.8 | |||
| Wood | Wood (clean) | 0.25-0.5 | |||
| Wood | Wood (Wet) | 0.2 | |||
| Wood | Metals(Clean) | 0.2-0.6 | |||
| Wood | Metals(Wet) | 0.2 | |||
| Wood | Brick | 0.6 | |||
| Wood | Concrete | 0.62 | |||
| Zinc | Zinc | 0.6 | 0.04 | ||
| Zinc | Cast Iron | 0.85 | 0.21 | ||