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 brake drums cast with steel centre plates, including tensile strength, hardness, and micro-structure analysis.
| Identifier | ExFiles\Box 120\1\ scan0229 | |
| Date | 19th October 1937 | |
| Mr. Knagg, Iron Foundry. c.c. to BY.{R.W. Bailey - Chief Engineer} c.c. to WHC. c.c. to Rm.{William Robotham - Chief Engineer} c.c. to Rm{William Robotham - Chief Engineer}/Mr. Martindale. c.c. to H.F.R. M.1,447 H1/EJW.1/GS.19.10.37. BRAKE DRUMS CAST WITH STEEL CENTRE PLATES. Further to Reports M.1,400 and M.1,426. Tests have been made on samples broken from a drum and submitted by you as representing a set of drums cast for experimental purposes. Tensometer tensile tests gave the following results :- Test Bar marked. Ultimate Strength Tons/sq.in. Brinell Hardness. T 16.5 252 L 16.5 253 The micro-structure is illustrated by the attached photomicrographs. The graphite is evenly distributed in short flakes and the matrix consists chiefly of finely laminated pearlite and sorbite, with small unconnected areas of phosphide eutectic. H1/EJW. | ||