21 years: 2005 - 2026

Blog: Rolex World's Records

Copyright © David Boettcher 2005 - 2026 all rights reserved.

First published: 15 August 2023, last updated 25 May 2026.

I make additions and corrections to this web site frequently but, because they are buried somewhere on one of the pages, the changes are not very noticeable. I decided to create this blog to highlight new material. Here below you will find part of one of the pages that is either completely new or I have recently changed or added to significantly.

This entry is from the page about Rolex.

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Rolex World's Records

Rolex watch case backs sometimes have inside a reference to a certain number of ‘World's Records’. It is not known exactly what records these claims refer to, but advertisements generally imply that they were records for accuracy of timekeeping.

Observatories and other establishments carried out tests on the accuracy of timekeeping of watches over a number days in different positions and at different temperatures, and issued results as a number of marks; the higher the number of marks, the better the performance. If a watch passed a certain threshold number of marks, it would qualify to be awarded a performance certificate.

In Switzerland, chronometer trials were conducted at the astronomical observatories of Neuchâtel and, to a lesser extent, Geneva. In England, watches were tried at Kew Observatory until 1912, when the trials moved to the National Physical Laboratory at Teddington, although they were still usually referred to as Kew trials. Watches that performed to certain standards at one of these observatories were awarded ‘observatory certificates’.

The towns of La Chaux-de-Fonds, Bienne, Le Locle and St-Imier each had a bureau d’observation des montres (watch rating office), usually attached to the town’s school of horology. These provided local watchmakers with an accessible means of having the timekeeping of their watches evaluated. These offices issued ‘bulletins de marche’ (performance certificates) after tests that were shorter and less demanding than observatory trials.

Initially, these watch rating offices were called ‘bureaux d’observation des montres’. In 1912, they were officially renamed ‘bureaux officiels de contrôle de la marche des montres’, removing the word ‘observation’ so that their performance certificates could not be called observatory certificates.

Seven World's Records

The first claim by Aegler and Rolex to a number of World's Records appeared in adverts in 1915. The first six of these can be identified from previous adverts as:

1. March 1910. A performance certificate awarded to an 11-ligne watch by the Bienne bureau d’observation. This was not the first 11-ligne watch to be awarded a performance certificate, but may have been the first at the Bienne office.
2. January 1913. A performance certificate awarded to a 9-ligne watch by the Bienne bureau d’observation. This was the first 9-ligne watch to be awarded a performance certificate.
3. February 1913. A Kew Class B certificate awarded to a 9-ligne watch. This was the first 9-ligne watch to be awarded a Kew certificate of any class.
4. March 1913. A Kew Class B certificate endorsed ‘Especially good’ awarded to a 11-ligne watch.
5. December 1913. An bulletin de réglage chronométrique awarded by the Neuchâtel Observatory to an 11-ligne watch. This watch had passed the more stringent observatory trial and could be described, in Swiss terms, as a chronometer.
6. July 1914. A Kew Class A certificate awarded to an 11-ligne watch.

It should be noted that not all Rolex watches entered at Kew passed the trial. On 3 January 1913, three 11-ligne bracelet watches were submitted for trial by Wilsdorf & Davis for the Rolex Watch Co. The first of these was entered for the Class A trial but did not pass. The second and third were entered for the Class B trial. The mainspring of one failed on 4 January, the second day of the trial. The other completed the trial but did not pass. The 11-ligne watch that was awarded a Class A certificate in July 1914 had been entered along with another in early 1914, when neither passed.

It is known that some of the watches entered for trials were regulated by Edouard Lüthi-Hirt, a professional ‘regleur’ (watch adjuster) working in Bienne, whose company also made tools for watch regulators. This use of an independent watch adjuster when high marks in trials were wanted was common practice amongst watch manufacturers, English as well as Swiss. Ordinary Aegler production watches were not adjusted to such a high degree at the time.

The nature of the seventh record is more difficult to pin down. The first advert claiming ‘Sept Records Universels’, which became Seven World's Records in English, was published by Aegler in January 1915. This advert contains the statement ‘Premier Concours de la Rolex Médaille d'Or, Berne 1914’ (First Rolex competition gold medal, Bern 1914). Since this was a ‘first’, it is plausible that this was the seventh record claimed.

Twenty World's Records

The published results of the Kew watch trials don't record any absolute records being set by Rolex watches, but the report in 1928 of the 1927 trials says

Another noteworthy result this year has been the award of a ‘Class A, especially good’ certificate for the 10¾ × 6¾ lignes (24 X 15mms.) rectangular bracelet watch sent by Messrs. The Rolex Watch Co., Bienne, which gained a total of 86.5 marks.

This is the event that Rolex advertised in 1928 as their 20th World Record. The watch had a 6¾ lignes movement measuring 15 by 24 millimetres and it was remarked in the letter communicating the results to Rolex that over the preceding 10 years no other watch of 13 lignes or smaller that had received a Kew Class A Certificate had been endorsed as ‘especially good’.

It appears that the World's Records claimed are not absolute records - the two Rolex watches entered by Aegler in the 1927 trials were placed in 31st and 39th positions - but rather records of accuracy for watches of their particularly small sizes. The achievement of a Kew Class A certificate endorsed especially good by a movement measuring only 15 × 24 millimetres was certainly a remarkable achievement. A later Rolex advertisement says that ‘No Wristwatch from 11-line down to 5½-line has at any time obtained a Kew Class A Certificate excepting the Rolex.’

An advert by Rolex in 1928 said ‘The Rolex factories have specialized in the production of small-sized movements since 1878, and the Twenty World’s Records which their movements have gained prove that they have attained to a position of pre-eminence, and constant research and experiments in the laboratories ensure that they will retain that supremacy. ‘The World’s Best by Every Test’ is no mere advertising slogan, but the essence of accomplished fact. Many hundreds of Observatory Quality 10½ and 8¾ line movements have been produced during the last few months. Each and every one of them obtained an individual Swiss Official Class ‘A’ Rating Certificate, proving that Rolex claims to unusual precision are founded as much on a generally superior method of production as on their World’s Records.’

Dating World's Records

The number of world's records claimed increases in steps from seven to thirty one. Knowing when the increment occurred can help to identify approximately when an otherwise undated watch was made.

World's Record stamps can be used to establish approximately the earliest possible date for a case, but not the last. Old punches could continue to be used, or cases not be used until some time after they were made.

By studying dozens of case backs with British hallmarks, the approximate dates when the increments of World's Records occurred. Until 1975, the date letters of hallmarks cover a two year period, British assay offices changed their date letter punches when new wardens were elected, part way through the calendar year. At the London Assay Office this was at the end of May, for most other offices it was the beginning of July.

• No claims to World's Records have been seen in Rolex watch case backs hallmarked before the 1923/24 hallmarking year.
• 7 World's Records: The earliest evidence seen for this claim is an advert from Janusry 1915. However, as noted above, it does not appear to have been stamped into Rolex case backs until 1923 or 1924.
• 16 World's Records: Earliest evidence seen is an advert dated 14 July 1926. There is some overlap between the hallmark dates of cases marked 7 and 16 World's Records, an 18 carat gold case has been seen with 7 World's Records and Dublin Assay Office hallmarks for 1928 to 1929.
• 20 World's Records: This refers to an Aegler Rolex wristwatch with a 6¾ ligne movement that in June 1927 was awarded a Kew Class A certificate endorsed ‘especially good’ for achieving 86.5 marks in the trials. There is some overlap between the hallmark dates of cases marked 16 and 20 World's Records. Cases stamped 20 World's Records have been seen with Glasgow Assay Office hallmarks for 1932 to 1933.
• 22, 23 and 24 World's Records:An advertisement dated September 1928 says ‘The Rolex Watch Co., Ltd. beg to announce their World's Records Numbers 22, 23 and 24 obtained in quick succession ...’
• 25 World's Records: Earliest evidence seen is an advert dated 1 December 1928.
• 27 World's Records: Earliest evidence seen is an advert dated 10 December 1931.
• 31 World's Records: Earliest evidence seen is an advert dated 22 October 1937.
• 34 World's Records: A single instance of a case stamped 34 World's Records has been seen, dated to around 1941, although the first use was most likely earlier than this date. No advertisements have been found with this claim. Further evidence is sought.