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Gruen Precision 24h World Timer ? a must (AWW 18)

6546 Views 6 Replies 5 Participants Last post by  saltddirk
Gruen Precision 24h World Timer - a must (AWW 18)


Name: Gruen Precision
Model Reference: ? (24h World Timer - named by me)
Movement: Gruen 731CA, Swiss Made, automatic, 17 jewels, 18000 bph
Time display: 24 hour 12 on top, minute, seconds
Date: at 3
Case: 10 microns gold electroplated with stainless steel screw case back
Size: 38 mm diameter without crown, lug to lug 48 mm
Height: 13 mm
Face: day and night marking, light cream and brown colors, outer world timer circle with cities names
Text on dial: Gruen, Precision, Swiss Made
Text on back: Gruen Swiss Made - 16 karat gold electroplate bezel - stainless steel back
Hands and markers: lumed black hours and minute hands, red sweep seconds hand
Water-resistance: ?
Crown: main at 2, additional cities bezel crown at 4
Crystal: domed acrylic crystal
Lug: 18 mm
Bracelet: solid stainless steel gold electroplated with tri-fold clasp, Gruen logo embossed


When I only started collecting 24h watches and studied, some watches described there raised my attention. You can't have all of them, but for me was obvious, that some watches are must - you just have to have them. Of course you need Glycine Airman or vintage Raketa with second time zone circle. Gruen Precision was for me another must. And when I finally saw that one American seller listed it I was ready to fight to the end. The end came with $460 plus shipping. Was it worth it? Read more.


Again, this is my first Gruen and I started with brand and history research. Gruen is of course German grün (green) and the company founder was Dietrich Gruen (Grün), immigrant from Germany.

The original "first" Gruen was active 1894-1958 and was located in Cincinnati, Ohio. Headquarters were in USA, but the main Gruen movement production site was in Biel, Switzerland. There they had so called Precision Factory producing higher level movements for Gruen. All the models equipped with these movements had "Precision" written on the dial.

In 1958 the company changed owners and was moved from Cincinnati to New York. The Precision Factory in Switzerland continued production until the end of "second" Gruen in 1976.

Very good source on Gruen history is Gruen Watch Company history: Gruen Curvex, Pentagon, VeriThin, Veri-Thin, Quadron, Cartouche, Ristside.
BTW. Small Biel (about 50,000 inhabitants) not far away from Swiss capitol Bern is a real watchmaker city. In Biel are located Rolex movement production, Swatch Group and Omega headquarters, and Glycine.

Rolex is now the owner of Precision Factory what is their administrative building.

Gruen History:
Above: The Gruen Precision Factory in Biel, Berne, Switzerland, in a photo from the 1929 Gruen Dealers' catalog. Note the "Precision" logo above the bottom two windows on the far left of the building.

In German, Gruen means "green." The company made a point of using green tile for the roofs of both Time Hill and the Precision factory, and Fred Gruen used green tile on the roof of his own house.
This watch here is produced by the "second" Gruen, probably on 70s or in the end of 60s. The heart is Gruen automatic 17 jewel movement 731 CA. CA stands for Calendar Automatic. The watch is in a very good shape and movement too. Inside the case everything was crystal clear as it was opened first time.

The movement is signed as" UN 731 CA, seventeen 17 jewels Swiss, unadjusted". On the rotor is written "Gruen Watch Co., Precision".
To set the date you have to move forth and back between 21-24.

The dial seems to be flawless. The case, case back, crystal and original bracelet are very good, only some minimal usage marks.

As far as I know this is the only full 24h dial watch from Gruen (very funny and highly collectable Gruen Airflight with changing hour numbers from 1-12 to 13-24 was just a 12h watch). This Gruen Precision 24h World Timer was available in gold plated and stainless steel versions.

I'm happy with this watch. For me the price was right. I think it is not easy to beat this price; you have to expect USD 500 or more. Today I was wearing it whole day. Of course, big gold wristwatch with gold bracelet is nowadays for many younger people too pompous. What the heck, I'm an old man and I can wear what I want.

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Re: Gruen Precision 24h World Timer - a must (AWW 18)

Seller's picture taken from auction. Gruen Precision from 1975 with box and papers.

Material property Watch
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