I have been reading the recent post on the meaning of adjusted,and wonder how Elgin timed their watches that did not have mean time screws. Did they do this by different balance screw weights? Also what is a studded mean time nut?

Elgin may have "mastered" precision "Vibrating" the balance wheel/Hairspring assembly perfectly enough that they need not have bothered with mean time screws to really fine tune the watch. Heck they might have had a precision "armbender" for all I know.

Some of my mid-1930's Elgins have steel threaded studs about 1/4 mm diameter jam threaded into the balance wheel at the cross arms and 90 deg away from the cross arms. Elgin assembled to these 1 each a threaded ID cylindrical gold "nut" that can be screwed in and out to adjust or regulate time accuracy. This is the same idea as the other manufacturer's mean time screws but a little more reliable as the threaded studs would not break off in the balance wheel as easily.

Thank you for your reply, David. I have a 571 BW Raymond that has four mean time screws. The 573 and the 575 Elgin that I have do not have mean time screws. The 573 is a 17 jewel movement with the micro regulator and is quite accurate.

The post WWII elgins are a completely different story. Sorry I did not go that far. To me the "5xx" series resemble Swiss more than US-Made movements. Not good or bad, just "different".

Plus the fact that the 571 is the only one of the three regulated for RR service, the 573 & 575 were not....

Regards,

Jerry