Rolex Clasp Codes Guide
Every Rolex clasp manufactured between 1976 and 2011 carries a stamped code on the inside of the hinge that identifies the month and year the bracelet was made. The code is one or two letters (the year) followed by a single digit (the month). A clasp marked OP9, for example, was manufactured in September 2006.
At NW Timepieces, we authenticate pre-owned Rolex daily and use clasp codes as one of several reference points when dating a watch. Below is the complete chart, plus how to read it correctly and where collectors most often get tripped up.
Where to Find the Clasp Code
On an Oyster clasp, open the clasp fully and look at the inside of the swing arm — the section that rotates against the bracelet. On a Jubilee bracelet, the code is stamped on the inside of the folding blade. You may need a loupe; the stamping is small.
Rolex Clasp Code Year Chart (1976–2011)
| Clasp Code | Year |
|---|---|
| A | 1976 |
| B | 1977 |
| C | 1978 |
| D | 1979 |
| E | 1980 |
| F | 1981 |
| G | 1982 |
| H | 1983 |
| I | 1984 |
| J | 1985 |
| K | 1986 |
| L | 1987 |
| M | 1988 |
| N | 1989 |
| O | 1990 |
| P | 1991 |
| Q | 1992 |
| R | 1993 |
| S | 1994 |
| W | 1995 |
| V | 1996 |
| Z | 1997 |
| Z-W | 1998 |
| X | 1999 |
| AB | 2000 |
| DE | 2001 |
| DT | 2002 |
| AD | 2003 |
| CL | 2004 |
| MA | 2005 |
| OP | 2006 |
| EO | 2007 |
| PJ | 2008 |
| LT | 2009 |
| RS | 2010 |
| CP | 2011 |
How to Read the Month
The single digit after the letter code is the month of manufacture, from 1 (January) to 12 (December). A few examples:
- OP9 = September 2006
- MA3 = March 2005
- DE12 = December 2001
- L6 = June 1987
2011 and Later: Random Alphanumeric Codes
Starting in 2011, Rolex switched to a random three-character alphanumeric code — examples include CX3, J4M, and 5AM. These codes are deliberately non-decodable from public reference data and are traceable only internally by Rolex. If a clearly modern Rolex (a 2012+ reference) has a sequential month-coded clasp, it's likely a service-era replacement rather than the original factory clasp.
The "S" Marker — Service Replacement
An "S" stamped on the clasp indicates that the clasp was replaced during a Rolex Service Center visit. This is normal on older watches that have been serviced through official channels — the original clasp may have shown wear and was swapped for a current-production replacement. A service-replaced clasp does not affect authenticity of the watch as a whole, but it does mean the clasp code can't be used to date the original watch.
Why Clasp Codes Don't Always Match the Case
It's common — and not a sign of inauthenticity — for a Rolex bracelet to be a few years older or newer than the watch head it's paired with. Rolex bracelets are often manufactured separately from cases and inventoried independently at the factory. Bracelets are also routinely replaced during service. When you authenticate a pre-owned Rolex, expect some mismatch and use the clasp code as one data point among several, not as the sole source of truth.
Frequently Asked Questions
Can I date a Rolex from the clasp code alone?
No — the clasp code tells you when the bracelet was made, not the watch head. To date a Rolex accurately, cross-reference the case serial number, the original warranty card or papers, the model reference number, and the clasp code together. Our Rolex Serial Numbers Guide covers case serials in detail.
What does it mean if there's no clasp code at all?
Pre-1976 Rolex clasps were not coded by month and year, so a vintage Rolex with no code is normal. If the watch is post-1976 and the clasp is unmarked, the clasp was likely replaced with a non-original or aftermarket part — worth investigating before purchase.
How do I know if my clasp is the original or a service replacement?
Compare the clasp code year against the case serial year. If they're within a few years of each other and align with the reference number's production window, the clasp is likely original. If the clasp code is significantly newer than the case or carries an "S" marker, it's a service replacement.
Are 2011+ Rolex bracelets less authenticatable?
The random alphanumeric system makes year-dating harder but doesn't reduce authenticity verification overall. For modern Rolex (2011 and later), the most reliable dating tools are the original warranty card, model reference number, case serial format, and the box paperwork. The clasp code becomes one of many data points rather than a primary identifier.
Where exactly should I look for the code?
On an Oyster clasp, flip the clasp fully open and look at the inside of the swing arm — the part that rotates against the bracelet when the clasp closes. On a Jubilee bracelet, look at the inside of the folding clasp blade. A jeweler's loupe helps; the stamping is intentionally small.
This guide is part of the NW Timepieces reference library. We're a family-owned Pacific Northwest dealer specializing in pre-owned Rolex, Patek Philippe, Audemars Piguet, and more. Browse our current pre-owned Rolex inventory, see our Rolex Serial Numbers Guide, or contact us for a second opinion on a watch you're considering.