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).
Specifications and advantages for experimental reamers and a left-hand taper tap.
| Identifier | WestWitteringFiles\E\June1920\ Scan19 | |
| Date | 1st June 1920 | |
| To WS. from E.{Mr Elliott - Chief Engineer} -2- E6/G4/6/20 Contd. The left hand flutes should be strictly at right angles to the threads to avoid obtuse cutting edges. The reamer should be sharpened by grinding the fronts of the teeth in each flute. Would you kindly have experimental reamers made and tested to this pattern. E.{Mr Elliott - Chief Engineer} It is a left hand taper tap, but the thread on the lands is right hand to give the proper cutting clearance to allow the reamer to advance. Advantages:- Does not attempt to cut over too large an area at once. Does not draw in or refuse to cut until forced, and then jam by taking more than its torsional strength. Each tooth is naturally graded in height and clearance, and naturally takes its share of the cut. Shavings would be narrow needles easily operated and got rid of. R.{Sir Henry Royce} | ||