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 boring and honing operations for Bentley cylinders, including tool specifications and procedures.
| Identifier | ExFiles\Box 146\2\ scan0256 | |
| Date | 3rd July 1937 | |
| W/P. To Sr/VA. from Rm{William Robotham - Chief Engineer}/Mths.{Reg Matthews} 1240- Rm{William Robotham - Chief Engineer}/Mths.{Reg Matthews}3/AP.3.7.37 BENTLEY CYLINDERS With reference to your memo Sr/VA.2/ET.25.6.37 requesting information on finish of cylinders, we give below the boring operations carried out by works. (1) Rough bore. (2) Fine bore (Krause fine boring machine) (3) Hone (180 grit hone, Carborundum Co.) (4) Finish hone (37500 J.{Mr Johnson W.M.} Crystolon hone, Norton Grinding Wheel Co., Birmingham) The full particulars of the finishing hone in case you wish to order some are as follows:- "Honing sticks for Micromatic Hones 5/16" x 7/16" x 4" B.M.E. 36 unmounted 37500-J-Crystolon. These are supplied by Norton Grinding Wheel Co., Birmingham. The first hone is to the same dimensions as above i.e. 5/16" x 7/16" x 4" but is 180 grit stone in Carborundum and can also be obtained from Norton Grinding Wheel Co., Birmingham. The procedure at the Works after fine boring is to use the rougher stone to bring the bore to finish size, the finishing hone is then used merely for polishing and does not remove any metal. Each bore is finished honed for 5 minutes to get the desired finish. Care should be taken at the end of the fine honing operation that the hone does not tilt and scratch the bore on removing. Rm{William Robotham - Chief Engineer}/Mths.{Reg Matthews} | ||