The difference between thick film and boundary film lubrication are as follows-
| Thick film | Boundary film lubrication |
|---|---|
| It is also known as film or hydrodynamic lubrication. | It is also known as thin film lubrication. |
| In this case, the coefficient of friction ranges from 0.001 to 0.03. | In this case, the coefficient of friction ranges from 0.05 to 0.15. |
| The lubrication should have minimum viscosity. | The lubricant should have more oiliness. |
| The lubricant neither gets absorbed on nor chemically reacts with a metallic surface. | The lubricants may be absorbed on or chemically reacts with metallic surfaces |
| The lubricating oil forms uniform film of a thickness more than 10000A in between two moving or sliding surfaces. | TThe lubricating oil forms uniform film of a thickness more than 1000A in between two moving or sliding surfaces. |
| The oil molecules are disoriented. | This lubrication is used in machines working under high load and slow speed. |
| This lubrication is used in machines working under light and high speed. | Bearing, gears, tractor rollers, lathes, railway track joints, concrete mixture etc. |