From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
The co-efficient of friction for various materials under dry and oily conditions.
| Identifier | WestWitteringFiles\R\2October1927-November-1927\ 26 | |
| Date | 19th October 1927 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Tsn. c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to RG.{Mr Rowledge} DA.{Bernard Day - Chassis Design} c. to E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} c. to OY. ORIGINAL Hs{Lord Ernest Hives - Chair}/Tsnl/LG19.10.27. CO-EFFICIENT OF FRICTION. X1109 X4222 We have tested the following materials both dry and oily in order to compare their co-efficient of friction. Red fibre. Bakelite. Agglomerated cork. Ferodo. Bronze. These materials were tested by resting a smooth flat block on a polished cast iron surface plate and putting on various loads. The effort required to start and sustain slow steady motion was measured. The condition of lubrication described here as 'oily' was that commonly known as 'boundary lubrication', and was obtained by first rubbing the block slowly to and fro until no oil was squeezed out. The oil used was Motorine 'C' at atmospheric temperature. Some difficulty was obtained in getting consistent results. When the materials were dry the co-efficient depended upon the state of polish on the surface plate; this was steadily improving throughout the tests. When oil was used, the coefficient was found to depend on the amount of oil present, and how long the block had been standing since last moved etc. The following table gives what we think are comparative results. The pressures used were varied from 2 to 10 lbs/sq.in. for all | ||