Acredito se referir à posição dos parafusos (11 e 3 horas)

Inferior angulated screws were longer at 6 o'clock (41mm) versus 5 (31 mm) or 7 o'clock (17mm). Perpendicular screws had similar lengths at the 11, 12, ...
www3.aaos.org/education/anmeet/anmt2007/poster/poster.cfm?Pevent=P345

After the establishment of a 3-o'clock portal, a specially constructed guide was used to place a pin at the 5-o'clock position. The distances of the pins ...
cat.inist.fr/?aModele=afficheN&cpsidt=1948635

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Note added at 14 mins (2008-08-08 19:06:36 GMT)
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Adoro referência que não sai...

With the crank pin hole positioned at 12 o'clock, the screw hole is located next to the crank pin hole at 9 o'clock. 1936-1940 61 OHV Flywheels: These ...
http://books.google.com/books?id=nHJsMYEnvZkC&pg=PA145&lpg=P...

For example: The wire sites shown are at 2 o'clock, 4 o'clock, 8 o'clock and 10. o'clock. Pins are larger diameter than wires and enter the extremity on ...
www.llrs.org/1995oct.pdf

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Note added at 48 mins (2008-08-08 19:40:49 GMT)
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That I should go out on the works twice a day (10 o'c am and 3 o'c pm) and take every man's time and the note of the work or nature of the work he was doing ...
www.murnane.org/maurice.htm