How to Identify Different Versions of Hamilton 987 Movements

The purpose of this article is to clear-up general misunderstandings about Hamilton 987 size 6/0 movements.

by Tom Adelstein

Much confusion exists about them. You need to know which 987 generation goes in which watches to make wise purchase decisions. Otherwise, you might win an auction thinking you bought a high priced model and later discover you bought a popularly priced wristwatch instead.

Hamilton produced six movements referred to as 987 calibers. They’re 17 Jewel movements and evolved from smaller pendant pocket watches. The company produced a size 6/0 movement for wristwatches known as the 986. Later, they produced a 19 Jewel version known as the 979. The 987 became the survivor but underwent various quality improvements over the course of its life cycle.

Hamilton Watches with 987 Movements
link to eBay search

The company made high-end wristwatches with 987 movements between 1924 – 1935. That changed when Wall Street Analysts spread the word that the country would enter the recovery phase of the business cycle in 1936. Hamilton’s management believed the same thing, which influenced changes made in their product strategy. Hamilton made the decision to enter the popular priced strap watch market with 10 karat gold-filled cases using 987 movements.

In the perception of consumers and Hamilton’s competitors, watches with 987 movements were commodities. Hamilton made significant enhancements to the 987, which improved its performance over it competitors. Hamilton believed that customers would be thrilled to buy a popularly priced watch with their best movement. When the company changed the letter affixed to the model, people thought the movement was downgraded. In fact, it was greatly improved.

Hamilton’s management expected consumers to return to jewelry stores and begin buying watches again. Unfortunately, the Depression didn’t just go away in 1936. The movement that some people believed help win the World War II, had an undeserved poor reputation between 1936 to 1941; until it drove military watches for the Allies. Even the UK bought Hamilton wristwatches with 987 movements for their pilots. That’s a pretty steep endorsement.

Hamilton also introduced its 14/0 sized rectangular movements – the 980 and 982 caliber models in 1936. They chose the rectangular movements for their high-end watches. That trend continued until 1941 when Hamilton shut down its consumer products group and dedicated its entire production facilities to the US Military. The Pentagon chose one of Hamilton’s 987 movements for all members of the armed forces at the start of US involvement in the war.

A colleague once told me to “stay away” from any 987 movements other than the original. Without much thought, I did that. I had no use for 987 movements with a letter next to the number. My colleague picked up that notion from his mentor, who picked it up from his mentor and so forth.

I found out that the oldest watchmaker of the bunch started practicing in the early 1900’s. He had no use for “them new-fangled Swiss improvements”. My colleague bought up all the original 987 movements he could find and used them in every 6/0 size case he had. I suggest that you don’t make the same mistake he did.

I wear an antique Hamilton watch daily – and why not? Compared to $5000 + wristwatches made and sold today, my 1938 Martin is a bargain. The US Military used that same movement in the watches our troops wore in World War II and from what I understand, they worked even when caked in mud.

987

Hamilton 987-987(x) movements can be found in wristwatches made from 1924-1948. When you begin to see a letter after the 987 it means improved friction jeweling. The first 987 (1924-1929) had bezeled jewels or the kind held in place by a small ring over the jewel hole and held in place with screws. Hamilton stopped making the original model 987 in 1929 and introduced the “improved jeweling” or what we call friction jeweling. The jewel is held in place by friction between the jewel hole and the stone itself. That version of the movement is denoted as a 987 F, which Hamilton stopped producing in 1935. That year, Hamilton introduced a Swiss Elinvar hairspring. Hamilton denoted that model as a 987 E, which they stopped producing in 1937. Hamilton began producing a movement with the Swiss Elinvar hairspring and a monometallic balance and was designated as the 987 A.

987 A

987 F

Hamilton produced the 987A for the military during World War II and continued production until 1948. The 987A was similar to the earlier 987 models but had an Elivar Extra hairspring. The “A” was a different design, and only a few parts were interchangeable with the earlier models. Hamilton produced approximately 490,00 model 987As.

987 E

Finally, Hamilton began producing a watch with a center or sweep second hand. That model carries the designation of a 987S. The Hamilton models with a sweep second hand (another military watch) were produced from 1940 to 1948. The 987A and 987S were fitted with Elinvar Extra hairsprings when they became available.

987 S

Hamilton also produced a 2987 version of the movement for military use. It’s quite different from the civilian model and has 18 jewels instead of the 17 jewel 987 movements. It was made for the Marine Corps between 1943-1945 in small numbers with approximately 3000 produced. Like the 987S, it had a sweep second and setting soldiers could use to synchronize time.

Marine 2987 with hack

2987 WWII Movement

Okay. Why is this information important? Well, let’s look at one example. I have a nice 1928 engraved Tonneau that’s becoming the watch I plan to wear daily. When I first opened the back, I found a 987 movement. I’ve looked at other models that have 987E and 987F movements. If you followed the discussion above, then you know the latter movements didn’t exist in 1928. What happened?

Watchmakers during the 1930’s simply replaced non-working 987’s with the newer version. People do something similar today. Instead of trying to fix a watch with an ETA 25.111 quartz movement in it, service people simply replace it. You cannot fix that watch for $79.95 and that’s what a new 25.111 costs. (A number of different brands use that movement – by the way.) In 1935, it was often cheaper to replace the movements than fix them. If the case was still good, put a new movement in it. Simple. After all, Hamilton shipped movements separate from cases.

Does replacing the movement hurt the value of a 1928 Tonneau? I haven’t thought about it. Maybe it does. In 1935, I would rather buy a movement than replace broken wheels and stripped clutches and so forth. The time, effort and cost would not have been worth it.

I see 1920 Hamilton models: Cushions, Hastings, Cut Corners, Barrels and so forth, with a variety of 987 movements. Would you have known the difference if you didn’t read this article?

Of course, purists would say that I’m blaspheming Hamilton’s sacred code of honor. They would probably go through the roof if they knew I’ve put a 987a in a Tonneau. Why would I go against the sacred handshake? I wear that watch, I’m not going to buy a Rolex, Tissot, Omega or a Khaki, but I want the best movement in it I can find.

What would you want your watchmaker to do if your Cartier Tank watch stopped working? Would you want to repair it for more than it originally cost or replaces the movement? That’s what I thought. Have fun!

Respectfully submitted

A Hamilton watchmaker finishing off a 987 movement