This for anyone with Hamilton large plate size 16 knowledge.

According the 2011 The Price Guide Hamilton made 670 large plate size 16 movements in three runs. 1st run was s/n 51,001 - 51,300, 2nd run 52,001 - 52,300 and the 3rd run 53,001 - 53,070. There is a picture on page 230 of a large plate s/n 52,135 movement. This is the same page I got this information from. On the following page #231 there is a Hamilton movement s/n 57,821. The one difference I can see in the two movements is the positive set screws. The large plate has an additional screw to lock the positive set screw. Other than that I don't see any difference. They are both different than the normal 17 jewel 16 size movements we are accustomed to seeing.

Why are the 670 called large plate and the rest that have the same plate design and look the same not large pates? In The Price Guide the 670 are listed as not having a model number and are listed as 16s. Yet in the Gelson list there is a model number associated with the same serial numbers.

I have one "Large Plate" as listed in The Price Guide and I have a few more 5 digit s/n's as the example on page 231. I see no difference in the two examples on page 230 and page 231. The later examples of Hamilton size 16 movements with 17 jewels is very easy to discern as probably 98% of the watches on eBay are of this type.

There is too much knowledge here on IHC185 for no one not to know the answer to this question. I imagine that it is not common knowledge so I am sure there will be more people interested in the answer than just me.

Thank you
Harry

Harry, here is a link to another thread where this was discussed:

large pillar plate link

Although this thread is about the 976/977, all the 16 size Hamiltons made before about 1900 had large pillar plates. The first Hamilton 16 sizes were designed by Henry J. Cain and fit the same 17 size cases used by the Waltham 1888 which also had the large PP.

Bob

Thank you Bob. Yes the large pillar plate I have is listed on the Gelson list as a 976. But I have a 972 and a 975 with the same plate design that according to The Price Guide are not large pillar plates. Thank you for the link I could not find it on my own.

Harry