Rolex Explorer I Three ERas

Collector Guide – Understand Vintage & Pre-Owned Rolex By Getting Familiar with Four-, Five-, & Six-Digit References

This guide will help anyone interested in any era of pre-owned/vintage Rolex begin their investigation.

Are You Lost In The Vastness of Used Rolex? Me too.

I’ve written definitive historical essays and guides about Rolex, but I still can’t claim to be even casually familiar with the countless references the brand has released for over a century. Friends of mine, however, rattle off Rolex reference numbers and affiliated esoteric details as if they’re describing an immediate family member. I find their knowledge of Rolex so intimidating that for many years I gave up on joining those conversations. I didn’t even know which specific Rolex references I might like.

My ignorance suddenly gave way to some confidence when I recently decided to buy a Rolex Explorer II Reference 16570. (Note the five-digits of the reference number.) This is a 39.2mm GMT with a fixed stainless steel 24-hour bezel. I got the black one (it also comes in white). The history and taxonomy of the Explorer II is well described in our guide, so I don’t need to bother with all that inscrutable minutiae here.

Rolex Explorer II From Three Eras
L-R: Four-, Five- and Six-Digit Rolex Explorer II. The author bought the middle one, a five-digit reference. (Images: Bob’s Watches)

The key to my newfound confidence was that I didn’t fuss too much over this purchase. Using my basic preferences for tool watches (size, style, features) and our Explorer II guide, I quickly identified what I wanted and located a fairly priced example. By moving quickly and not overthinking it, I also happened to realize that I broadly prefer five-digit Rolexes. Not four-digit (too old), not six-digit (too blingy), but those classy solid five-digit Rollies. 

Maybe understanding Rolex’s vast back catalog is easier than I had imagined!  You really just have to know about: four-, five-, and six-digit references to get started.

Roughly this is how the reference numbers play out by year:

  • Four-digit Rolex – 1950s to 1980.
  • Five-digit Rolex – 1980 – 2000s.
  • Six-digit Rolex – 2000s-preseant.

What The Rolex Reference Numbers Tell Us

Though there is a world of vanishingly small (and arguably insignificant) details one can eventually learn about every Rolex reference, any given Rolex since the 1950s will either have a four-, five- or six-digit reference number. That number of digits will tell you quite a lot about the watch because Rolex tended to introduce significant changes to the models when those reference numbers took on a new digit. The entire Rolex catalog would shift at roughly the same time, though it took a few years for the whole catalog to transition.

Rolex GMT Masters Three Eras
L-R: Four-, Five-, and Six-Digit Rolex GMT Masters. (Images: Bob’s Watches)

So-called transition-year Rolexes are sometimes a mash up of new and older parts, often throwing even experienced collectors into a tizzy of speculation and doubt. However, once the transitional period has settled (that is: once Rolex used up old parts) the catalog tended to stabilize again and become relatively consistent.

It would be both beyond the scope of this article, as well as an uncareful generalization, to say definitively what changed when Rolex added a digit to the reference number. However, we can safely point to two relatively consistent changes: usually a movement was upgraded and/or the case size or shape was changed.

With movement upgrades we usually saw a new feature: for example, between four- and five-digit Datejusts a quickset date was added (~1978-9). The quickset feature is a big reason I’m a five-digit guy. With the GMT Master we saw a quickset date and a jumping hour hand added when the four-digit Reference 1675 gave way to the five-digit 16750 in 1980. Eventually these kinds of upgrades worked their way across the entire catalog.

Rolex Datejust 36 From Three Eras
L-R: Four-, Five, and Six-Digit Rolex Datejusts. (Images: Bob’s Watches)

Rolex cases don’t always get larger when the brand adds a digit to the reference, but the cases almost always get little tweaks (added crown guards, thicker or skinnier lugs, and so on). Other physical features may also change, such as the addition of polished Cerachrom bezel inserts instead of aluminum coming on six-digit Rolexes (another reason I’m a five-digit guy, because I don’t like the bling of polished Cerachrom). Dials seem to always be changing in various large and small ways, as well, but don’t let all that intimidate you.

If you’re interested in a specific Rolex model, you will do well to first just think in terms of four-, five- and six-digit serial numbers. This will help guide your understanding of what you’re seeing out there in the vast expanse of millions of pre-owned and vintage Rolexes.

Rolex Submariner From Three Eras
L-R: Four-, Five- and Six-Digit Rolex Submariners. (Images: Bob’s Watches)

What Rolex Reference Numbers Feel Like As The Digits Increase

I’m going to generalize about the vibe of the four-, five- and six-digit Rolex references. While the vibe does seem to permeate the entire Rolex catalog, the changes affect each model a bit differently – so keep that in mind. I make these general characterizations to facilitate the first cleavage of the massive pre-owned Rolex market. Let’s give it a go.

The Warm Vintage Vibe of the Four-Digit Rolex

By now, all four-digit Rolex references are bonafide vintage watches, and they often look old, too. There is a kind of warmth to the four-digit watches, which is partly due to the older design features (like pie-pan dials on four-digit Datejusts or gilt dials on old Explorers), but patina also plays a big role here.

Tritium lume is common before 1998-ish, and tritium is always on four-digit Rolexes (tritium was also prevalent during the first part of the five-digit era). By now, that tritium is no longer luminescent and it has aged to a yellowish color. That aged look creates a super chill vintage vibe.

Rolex Four-Digit References From Three Eras
L-R: Four-Digit “Red” Submariner, GMT Master and Datejust (with linen dial). Note the aged tritium markers on the first two models. (Images: Bob’s Watches)

Many older dials were lacquered with nitrocellulose, which yellows with UV exposure, softening dials and making them look yellowish – especially over white and silver dials, but also champagne and even black. This yellowing is also charming and warm, and it goes nicely with the aged tritium.

Rolex Four Digit References
L-R: Four-Digit Explorer I, Daytona, and Oyster Date. These dials each show a warm patina. (Images: Bob’s Watches)

For daily use, four-digit Rolexes are fine, but they lack some mechanical features – especially the quick-set date. The movements in four-digit Rolexes can also be harder to get parts for and thus more expensive to service. 

I don’t wear Rolexes on bracelets, but I suggest that those who like bracelets should get to know more about what changed from four-to-five digits for whatever reference you’re interested in. Things like solid end and middle links are a big deal to bracelet lovers, as are the various changes to the folding clasps (stamped vs. extruded, various locking mechanisms, expansion systems, etc…).

An acceptable amount of bracelet stretch for a four-digit Rolex. (Image

By modern standards, four-digit bracelets feel flimsy – perhaps charmingly so. The hollow links make them lighter, which feels nice on my wrist, even if they’re a little jankey. And there’s usually “stretch” in a well worn older Rolex bracelet from a four-digit reference.

In summary, a four-digit Rolex is an old, vibey, warm and relatively jankey thing. They’re very charming, but are basically antiques.

The Classy Tool Vibe of the Five-Digit Rolex

Unlike the four-digit Rolexes, I find the five-digit models feel perfectly modern, but not 21-st century modern. I am, as I’ve already noted, a five-digit guy. Let’s look at why.

The sizes of the various five-digit models are great. My new 16570 Explorer II measures just 39.2mm across, and it’s one of the most svelte and comfortable watches I’ve ever worn in the 40mm zone. Five-digit Submariners and GMT Master IIs are similarly sized, and they’re all just beautifully proportioned. Not too big, not too small; not too vintage, not too modern.

Rolex Five Digit Referencees
L-R: Five-Digit Rolex Explorer II, Submariner Kermit) and a Sea Dweller. (Images: Bob’s Watches)

Functionally, most of the annoying limitations of the four-digit models are changed with the five-digit Rolex models – especially the quick-set date (but also other things you can learn about later once you dive deeper into a specific reference). More advanced materials start showing up in five-digit movements, adding to shock resistance and a-magnetism.

Super-LumiNova shows up around 1998 on five-digit models, and it not only holds a charge better than tritium, but it stays white over time, which is well suited to these watches crafted in 904L steel which pretty much looks brand new year after year. The same can be said of Rolex’s gold models, too, unless they are especially beat up (not usually the case with gold watches, though). 

Bezel inserts on five-digit Rolexes are still in aluminum for the Submariner and GMT Master, and for me this is a very important distinguishing trait for those references. Aluminum is a relatively mellow looking material, and the polished Cerachrome of the six-digit Rolexes is a bit blingy to my eye.

Rolex Five Digit References
L-R: Five-Digit Rolex GMT Master (coke), Turn-O-Graph (a.k.a. Thunderbird) and Daytona. (Images: Bob’s Watches)

The five-digit Rolexes represent an era that is vanishing before our very eyes. This is the late-late 20th century turning into the 21st century, a time when Rolex still made great tool watches you could just go buy, an era before everyone was staring down at pictures of their watches on their smartphone, and era just before the Second Gilded Age went full tilt and Rolex began excluding so many of us.

That last part is important in terms of vibe. The five-digit era ended just before Rolex fully embraced “exclusive luxury” practices it currently upholds. Waiting lists, blinginess, and bragging about which famous person wore which Rolex to which exclusive event had yet to creep into the world of the Rolex sports watch – or even the dressier Datejusts and Presidents (and Cellinis, but no one really thinks about those much).

L-R: Five-Digit Rolex Datejust, Submariner and Day-Date (a.k.a. President). (Images: Bob’s Watches)

For me, the five-digit Rolex really is what our resident Rolex expert Greg Bredosian calls “the sweet spot.” It’s neither totally vintage nor brand new and blingy. Five-digit Rolexes bring a lot of technology and refinement, but they still feel more or less like a rather expensive yet reliable tool for everyday use.

Six-Digit Rolexes – The Number of The Beast

My beloved five-digit 16570 Explorer II is now designated the 226570, measures 42mm across and sports a signed rehaut (ROLEX ROLEX ROLEX….). I wore one for a week, and I didn’t like it because it was almost like a cartoon compared to the five-digit predecessor. That 42mm Reference 226570 seemed to broadcast itself out to the world and say “I’m a recent model Rolex! How you doing?”

Rolex Six Digit References
L-R: Six-Digit Rolex Submariner, GMT Master II (Batman) and DEEPSEA Sea Dweller. (Images: Bob’s Watches)

But however I personally felt wearing a six-digit Rolex, in terms of vibe it’s safe to say that the six-digit Rolex models are louder, larger, more fashion-forward, and less tool-ish than their five-digit predecessors.

Why is that? Part of it is that most modern six-digit Rolexes are the largest version of that model to date, and the other reason is that finishing, lacquers, gold indicator surround, and polished Cerachrome have made modern Rolexes very shiny. They glitter. This isn’t tool-watch territory to my eye, and I think this blinginess is reflective (pun noted) of Rolex’s emergent exclusivity as it completes a decades-long transition from a high end tool watch company to an exclusive luxury brand.

Rolex Six Digit References
L-R: Six-Digit Rolex Datejust 41, Sky Dweller (a.k.a. Dead Russian Oligarch) and Day-Date 41. (Images: Bob’s Watches)

So, no I am not a six-digit guy because of the vibe, but that doesn’t mean these watches don’t have a lot to recommend themselves. They’re built and regulated to even higher standards than the five-digit models, carrying Rolex’s Superlative Chronometer program certification which guarantees daily precision of -2/+2 seconds per day. Cerachrom is virtually scratch proof, bracelets have evolved wonderfully, and so on. Rolex has not stopped advancing their technology, no matter how much the brand seems focused on exclusive fashion these days.

Rolex Six Digit References
L-R: Six-Digit Rolexes, including 2023’s Puzzle Day-Date, a Yachtmaster II, and a Hulk Submariner (Images: Bob’s Watches)

How Many Digits Are You?

I do think this is a very good question to ask yourself if you’re intimidated by the Rolex pre-owned market. You won’t find your exact watch this way, nor will you learn about all the little things that make one Rolex reference different from another. But you will have cleaved the millions of pre-owned Rolexes into three distinct categories, and from there you can navigate into the model you’re interested in, and from there into the exact reference you might prefer.

Gold Rolex Bezels
(Image: Rolex)

I didn’t really understand that I was a five-digit guy, and now that I know I am I find the whole enterprise of shopping for a pre-owned Rolex entirely do-able.

I sincerely hope this paradigm helps you out as well. Happy horological hunting.