I was pleased to receive a short acknowledgement on p43
For the benefit of anyone who is interested …
The patent, GB661824 (A), can be found here: **LINK**
… and it surely a novel use of case-hardening.
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The 'Tension Files' were originally available in three grades: **LINK**
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… and does anyone else remember the plastic-handled round files, which could be bent to shape ?
MichaelG.
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P.S. To the best of my knowledge, genuine ABRAFILES have not been manufactured for several years, so any on the market will be 'old stock'.
Edited By Michael Gilligan on 11/07/2018 21:02:02