I just finished a tedious project of sorting timing washers and thought I would share my new-found information. I've accumulated several Newall #345 sets, the ones that go from bottle #1-12, with the first four being for 18-16S movements. However, I've found out the hard way that none of these boxes actually had consistent washer sizes in any given bottle, they were all a mixed-up mess. This made it frustrating to use them to correct timing, snce I never really knew what effect any washer would have and they all look pretty much the same. I could not find any information at all on what the sizes were supposed to be, so I decided I had to sort through all of the washers for at least bottles 1-4, the sizes which I use most anyway, and arrange them by physical measurements. Here are my results:

All four bottle 1-4: outside diameter about 1.0mm
inside diameter about 0.5mm

Bottle #1: 0.036 - 0.044mm thick, mostly 0.042mm
Bottle #2: 0.058 - 0.072mm thick, mostly 0.062mm
Bottle #3: 0.086 - 0.096mm thick, mostly 0.092mm
Bottle #4: 0.110 - 0.132mm thick, mostly 0.120mm

By "mostly" I mean, the majority of the washers in that grouping were that thickness, but they could vary over the size range shown. Hopefully others will find this helpful, especially if you have a "random" assortment of washers like I did, so that when you select one you can now compare it and determine which bottle/size it should have been, and what timing effect to expect from a pair of them.

Richard, I have addressed the idea of sorting Balance washers as something I would attempt just AFTER I had counted how many Angels could "dance on the head of a pin" . . . you are awesome!

Thanks very much for the compliment, David, but I'm afraid I was home ill and just wanting something mindless to do. Sorting timing washers definitely qualified!