I intend to replace the mineral glass watch crystal (which is broken to pieces) on this old Seiko (7009-3119). The thickness is 1.25mm, but how do you properly size the diameter for pressure fitting tolerances ?
With the calipers I measure 29.4mm. Should I get a 29.5mm crystal ? Do you size it 0.1mm over ?
Then I am reading --> here 29.2mm and I get confused. Is this the manufacturer's recommendation ?
This model has a removable gold-plated coined bezel. The bezel has a plastic o_ring on the outside that pressure fits to the case. The bezel also has a hard to see plastic o_ring on the inside (in a groove) where the crystal sits and it is pressure fit with the crystal. The correct sizing for the crystal is 29.5mm diam and 1.2mm thickness.