Abstract
A new machine is described by means of which static friction between contacting surfaces separated by lubricating films of thickness approaching molecular dimensions can be measured with considerable precision. In a test run, a number of spot determinations of the static coefficient are made at closely spaced points over a short rubbing track not exceeding a few thousandths of an inch in length. The individual “slips” at the contact may be as small as 0.0002 in. The unit pressure is of the order of 500 psi. A significant correlation between static friction and the molecular structure and dimensions of a pure hydrocarbon lubricant has been established. Exceedingly smooth contacting surfaces overlaid with monomolecular films of strongly polar hydrocarbons have exhibited the phenomenon of vanishingly low static friction.
