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The variation in the threads of the dowel screws of spectacle frames
Author(s) -
Davidson Mark P.,
Mitchell John W. C.,
Walsh Glyn
Publication year - 1997
Publication title -
ophthalmic and physiological optics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.147
H-Index - 66
eISSN - 1475-1313
pISSN - 0275-5408
DOI - 10.1046/j.1475-1313.1997.96000452.x
Subject(s) - dowel , spectacle , variation (astronomy) , optometry , orthodontics , computer science , mathematics , medicine , engineering , structural engineering , physics , astrophysics , economics , market economy
Summary British Standards specify a very small number of screw sizes as being acceptable for use in spectacle frames. We have measured the screw sizes of 50 frames, selected at random from the stock of Glasgow Caledonian University Clinic and have shown that very few of the screws used conform to these standards.