Hi, I just found an Elgin grade 109, class 60, exactly like my Pansy's, and mine are listed as a size 0s, in Wayne's Elgin database.

When told that it was a 3/0 I checked, and it is a 27.94 mm movement, so it makes it a 3/0 not a 0s, I THINK?

Does that make ALL of Wayne's posts on the 109/60 incorrect? or what.
The message I got was from a guy in the UK when I asked about it, and mentioned that it's listed as a 3/0 and not an 0s. His measurment is correct unless I'm doing something wrong.

I'm measuring from rim to rim of the watch, right at the edge of the movement while still in the case. Is this right?

Are all of my Pansy's a 3/0 or a 0s?

I can pick out a 109/60 in a heart beat, but never thought to check the size with my measuring tool before.

Boy is this going to mess up my database. I have lots of 109/60's !!!!

I haven't studied Elgins as much, but I know that Waltham took some of their basic 0-size movements and trimmed them a little smaller to make it a 3/0. It is still the same movement but listed as 3/0. Waltham did not use grade and class as Elgin did, so I am not sure if it is comparable. But it may be that Elgin took some of their standard 0-size movements and trimmed them smaller to fit in a smaller case.

Sheila;
Below is a sizing chart that I came across several years ago. Yes, 27.94 millimeters is considered to be the equivalent of the American 3/0 size.

You may have stumbled onto an interesting correction of Wayne’s database. Although he does indicate that the database on his web site is perhaps one of the most complete to be found, he does not claim it to be infallible (to quote him “I have found a fair number of errors in Elgin's own serial number lists.”). If the Elgin records were compiled later than the mechanisms were produced then you may have stumbled onto a fault in the memory reconstruction of the records. The source records would have contained the disparity, not the transcription. Such an error would be almost impossible to detect and would be reveled only by having a number of 109/60 mechanisms in one collection to compare.

On the other hand, only the one record of that specific mechanism may be in error. There is only a 1.68 millimeter size difference between a 0 size mechanism and a 3/0 mechanism. That size difference could be optically ‘disguised’ by the movement’s case. So, you would need to measure all of your 109/60 mechanisms to determine if the error is confined to the record of that single timepiece, or if the general description of the 109/60 mechanism is possibly at fault.

I think you said you measured across the back of the movement. The size measurement is across the dial. The dial plate is larger than the back plate to facilitate putting the movement in the case. 2/30" is the amount required for a 0 size movement. The difference varies a bit with watch size.

2/30 would cetainly account for the size variance.
Tom;
Do you have a more extensive listing of the front plate versus back plate size differences that you could post? It would be a great aggravation saver.

This is from Wayne's site, and I'm going to measure all of them and let everyone know what I find out.

What Exactly Is Being Measured?
The measurement to determine the size is supposed to be through the widest part of the narrowest diameter. If the watch movement is round, then you should measure across whichever plates are the widest, whether the plates are on the top or the bottom or in the middle. If the movement is rectangular, barrel shaped, or oval, you still have to measure across whichever plates are widest, but you have to use the narrow cross section which still goes through the center of the watch. So, if you extend the length of a rectangular movement, you won't change the size. If, instead, you change the width, you will change the watch size. Did I mention that watch sizes are strange?

Sheila;
I admire your pluck, but I think that Tom has already 'pegged' the difference. The dial plate being wider for casing purposes would match the requiements that Wayne mentions. The 2/30" variance would make difference. In the respect of seeing for yourself, you are like me, but please do not make measuring such a mania that you check into a room with rubber wallpaper!

Hi Tom,
Thank you, sorry I didn't see your post when I was in last time I posted. Great information to know. That sounds right to me!

Mark, No worry, I'm not freeking out just wondered if I was measuring right.
However, those in Europe do measure that way, so I will have to watch for that in the future when I'm considering a watch from now on.

By the way, even when I measured using the dial it still didn't come out right!!! BUT....

I'm not great at measuring either