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).
Test results for 'FLEXKO' brake lining material, detailing wear and friction co-efficient.
| Identifier | ExFiles\Box 141\3\ scan0148 | |
| Date | 14th February 1933 guessed | |
| "FLEXKO" BRAKE LINING. A more flexible variety of the "SAFEGUARD" quality is also made, known as "FLEXKO". This material has a high co-efficient of friction, and on account of its being less dense than the standard "SAFEGUARD" Linings it is used with much more satisfaction on some motor vehicles of American origin. Tests carried out on "FLEXKO" give the following results: Thickness Test Mark Dimensions Before After N.G. .76 x 2.97 .289 .219 N.G.2 .742 x 3.0 .288 .198 N.G.3 .758 x 3.0 .290 .244 N.G.4 .758 x 2.98 .292 .208 Average .290 .217 Average wear = .073 inches. Area of test pieces = 9.02 sq. ins. Duration of Test = 5 hours Total work absorbed = 90,000,000 ft.lbs. = 9,990,000 ft/lbs. sq.in. Wear Figure = .00731 = wear in inches for the absorption of 1,000,000 ft.lbs. of work/sq.ins. Time Load Speed Temp. at Co-efficient of Friction hr. - hr. lbs/sq.in. ft/min. end °C Max. Min. Average 0 - 1 13.3 4320 80 .642 .45 .546 1 - 2 13.3 4325 75 .634 .4 .517 2 - 3 13.3 4360 85 .584 .467 .525 3 - 4 12.3 4270 80 .78 .617 .698 4 - 5 11.1 4250 95 .8 .72 .76 Average 12.66 4305 .609 | ||