This blog entry is on the markings on the case back of the G10 field watch issued by the British Ministry Of Defense. This is based on my readings and on the case back of my small collection of G10 watches. I have G10 watches made by CWC and Precista.
Typical British W10 markings:
(Pheon/ Broad Arrow)
The first of characters indicates that the watches were ordered by the respective branch of the military, i.e. they paid for it but the watches were not exclusive to the branch. A 0552 watch could and can be issued to the Army or Royal Marines.
W10: Army (photograph above)
0552: Royal Navy
0555: Royal Marines
6B or 6BB: RAF
The second set of characters:
6645 is part of the NSN. It is the NATO Supply Classification identifier for timekeeping instruments.
The third set of characters:
99 is part of the NSN. It is the country code.
The Country Codes:
00 United States
01 United States
18 South Africa
98 New Zealand
99 United Kingdom
The second line of characters, 541-5317, are the rest of the NSN. This is followed by the Pheon (Broad Arrow) and the last line will be the serial number/ two digit year.
Location of the Pheon. Generally in quartz watches, the pheon will point towards the crown and in mechanical, it will be between the second and third line. But as can be seen in the first photograph, on the Precista, the Pheon is between the second and third line.
There are variations. Look at the 6BB photograph.
The NSN is all in one row and there is no hyphen between 541 and 5317. The location of the Pheon is between the first line and the second. This is on a CWC thick case.
Both the 0552 and 0555 have the same markings,
where the third line is the serial number and the forth is the two digit year. The Pheon is pointing towards the crown. The photograph below show a 6BB in the same configuration.
Photograph: Anchor Supplies
There is no slash between the serial number and the two digit year. Pheon pointing towards the crown.
There is a slash between the serial number and the two digit year.