What is a true Hamilton 992E movement?

March 18, 2011, 23:51

Robert Loe

I have Hamilton 992, S/N 2552054 which places it about 1934. The Elvinar hairspring was introduced about 1930-31. There is no Elginar marking on the movement.

1. Is my watch a 992E or just a plain 992?

2. Does my watch have an Elvinar hairspring?

March 19, 2011, 00:59

Buster Beck

Your watch was made in 1930

The first 992E was also made in 1930-1931 and the first serial number was 2581001

Your watch is a 992L [Lever set] and isn't a 992E

Your watch does not have an elinvar hairspring unless someone has replaced it since it left the factory. If it is an elinvar hairspring it would be a white metal except for some that were dyed blue at the factory since old watchmakers at that time were a crabby bunch that hated "modern" changes

regards,
bb

March 19, 2011, 04:32

Lindell V. Riddle

Robert,

Buster is essentially correct, here is some additional information that might help further.

To begin with, your movement number 2552054 is from a 992 run consisting of 2552001-2555000 in 1930 production. Carefully study the numbers and notes on our page 20 of the Hamilton Movement Number Listings Preserved by John F. Gelson and you will recognize that any list simply based on the years and numbers cannot be accurate. All watch companies including Hamilton habitually assigned or "blocked" numbers in advance of production so it is confusing, that's why the "Gelson List" is so very, very valuable to Hamilton collectors and researchers.

Your movement should correctly have a conventional split balance wheel such as indicated by the red arrow in the left image below. Notice the Elinvar shown on the right has a solid balance wheel with different style spokes and a clear "ELINVAR" stamped on the pallet bridge. Every one of the 992-Elinvar and 950-Elinvar movement balances will look like and have each of the features you see on the right. As Buster alluded to Hamilton met resistance when showing their first Elinvars because of the natural color gray rust-resistant hairspring. Retailers and Watchmakers demanded the revolutionary new Elinvar hairsprings be dyed blue, and so they were. This changed with "Elinvar Extra" at 992B introduction in 1940 but with the exception of replacements and factory retro-fits every 992-Elinvar and 950-Elinvar can be expected to have blued hairsprings. Our comparison below may be helpful in recognition.

One further note, it appears that Hamilton supplied the "Elinvar" marked pallet bridge as a service part for general replacement after supplies of the plain one was exhausted, for that reason we may come across an occasional Non-Elinvar with an Elinvar-Marked Pallet Bridge. Another reason for everyone to commit this information to memory or some of us print portions of this topic for servicing reference.

Lindell

Non-Elinvar Split-Balance at arrow and "Elinvar" on the right...

March 19, 2011, 10:58

Jared Brinker

Robert-

I first look up the serial number, if it is available. If it is not available, the second item to look at is the pattern of the damasking on the movement. A 992E movement will have a straight line pattern to it, but will be very wide between the defined "lines". A standard 992 will have an ornate pattern to the movement (earlier models) or a straight line pattern to it with narrow bands. The difference in the straight line patterns can be seen in the pictures Lindell has posted. If you look just below and to the left of the frame screw in his pictures, you will see that the defined "lines" across the 992 movement are almost twice as close together on the movement vs. the 992E movement. From there it is just down to wether or not someone has switched parts between another watch at some point.

March 19, 2011, 13:17

Larry Lamphier

Jared, That is true on the LATER model 992E movements. The early movements had the same narrow lines as the 992. I'm not sure when they started the wider ones, but I'm sure someone can add to this.

Regards,
Larry

March 19, 2011, 19:32

Eugene Buffard

I have serial # 2582929 1St Run Narrow pattern 1930-1931.

I have also #2592565 2nd Run Wide Pattern 1930-1935.

I am under the impression that the First run is narrow. The second run is wide. If some one has a narrow pattern from the second run I'm sure every one would like to hear from you.

Of the 5-992E I have they all have the solid balance and the Blue hairspring.

The latest one I picked up was today. Movement # 2627513. Case H204685. Broken staff. But case, dial, and movement all in excellent condition. Movement and Case from the same year.

March 21, 2011, 17:58

Robert Loe

Thank all of you for sharing your knowledge of what some might consider to be an arcane topic.

I had no idea of the subtle differences between these watches, even though they share the 992 model number.