GMT Master and GMT Master II Reference List

[PlanetZoom]

This thread is a compilation of information about the Rolex GMT Master and GMT Master II.

There is a lot of content here, so to help find relevant information I've added an index at the end of this post.

History of Rolex GMT Master

The Rolex GMT Master was first issued in 1954. It was originally designed as an aviator watch in cooperation with Pan American Airways. In the 1940s and 1950s, flying distances got longer and the pilots travelled through multiple time zones. In the 1950s, Pan Am asked Rolex to develop a watch that could tell different times simultaneously.

The watch was a breakthrough for pilots. The newly introduced fourth hand, in conjunction with the rotating bezel, allowed pilots to display two time zones.

The watch received its name from Greenwich Mean Time (GMT). At that time, GMT was the world's time standard and was used in aviation planning.

The purpose of the two-tone bezel was to help the wearer distinguish between day and night.

There have been relatively few changes in the watch over the years. The original bezel was a Bakelite bezel, which was replaced in 1956 with a stronger metal bezel. In 1959, a crown guard was added, along with a dial inscription that said "Superlative Chronometer Officially Certified." Different bracelet options were offered, including leather strap, jubilee, and oyster bracelets.

GMT Master compared to GMT Master II

In 1983, Rolex released the GMT-Master II. The GMT II looked virtually identical to the original GMT . The differences were on the inside. The GMT used a quickset date and relied on a rotating bezel to read a second time zone. The GMT
II has, in addition to a rotating bezel, an independent hour hand and 24 hour hands, so the wearer can compute a third time zone. So the movement of the GMT II includes a quickset hour hand that is locally adjustable. On the GMT II, local time can be set without stopping the second, minute or 24-hour GMT hand.

The GMT and GMT II were simultaneous produced until Rolex discontinued the Master in 1999. The GMT II is a little thicker than the Master.

Here is a side-by-side comparison (GMT on the left, GMT II on the right):




Index of information in this thread

GMT 6542
GMT 1675
GMT 16750
GMT 16700
GMT II 16760
GMT II 16710
GMT II 16710 bezel insert numbers
GMT II 16710 variations and anomalies
GMT II 116710

GMT reference timeline
GMT serial / year guide
How to determine a Caliber 3185 from 3186 through crown rotation
Three New GMT II Models Released March 2018

 

[LinoItalia]

Follow

 

[PlanetZoom]

Here's a really cool GMT. A rare 1675 with a blueberry bezel.

 

[PlanetZoom]

GMT Reference Timeline

 

[PlanetZoom]

GMT Serial / Year Guide

 

[PlanetZoom]

GMT 6542 aka Pussy Galore

Production Period: 1954-1959
Model Name: Rolex GMT Master
Caliber: 1036 (1954-1959), 1065 (1957-1959), 1066 (1957-1959)
Pressure proof to 50m/165ft

Launched in 1954, this was the first GMT Master. It was eventually replaced by the 1675.

It was developed on the basis of a regular Turn-O-Graph (Ref. 6202). The modifications were a different bezel and a modified movement. Designed to be the watch of choice for Pan-Am pilots, the GMT Master became the benchmark when it comes to two-timezone watches.

Despite being the first, what mainly sets it apart from later versions of this model is the bakelite bezel. The numerals inside the bezel are actually filled in with Radium. The thought behind it is that even in low-light conditions you could easily check the time in both time-zones. While this must have looked amazing when these watches were first issued, it was also a cause for trouble. Bakelite is by itself already quite brittle, and combined with the radioactivity of the Radium made it that Rolex discontinued this bezel quite quickly. In 1956, Rolex replaced it with a metal bezel.




In addition to replacing the bezel material, Rolex also outfitted the ref. 6542 with three different movements. First came the Caliber 1036, then the Caliber 1065, and finally the Caliber 1066. Of course, each of these was an automatic movement powering the time, date, and extra 24-hour hand. The 24-hour hand and the traditional 12-hour hand were directly linked. Thus, the wearer would set his local time on the main dial and then adjust the bezel to line up with the GMT hand accordingly to correctly indicate his second time zone.



The first GMT-Master was waterproof to only 50 meters and didn’t include any crown guards. This would eventually change where the GMT-Master would boast increased water resistance and crown guards were eventually introduced to future GMT-Master references. The GMT-Master ref. 6542 was in production until 1959, after which the then-new GMT-Master ref. 1675 took its place.



The name Pussy Galore originates from a character known by that name (played by actress Honor Blackman) who wore the watch in the James Bond movie Goldfinger in 1964.

 

[PlanetZoom]

GMT 1675

Production Period: 1959-1980
Model Name: Rolex GMT Master
Caliber:
- 1565 (1959-1964) 18000A/h
- 1575 (1965-1980) 19600A/h (hacking introduced 1971)
Pressure proof to 50m/165ft
Bracelet: Oyster 78360, Jubilee 62510
Glass: Acrylic crystal
Indexes: Tritium
Dimensions: 40mm diameter, 12mm thickness
Lug width: 20mm

The Ref 1675 was introduced in 1959 and was produced until 1980. It replaced the Ref. 6542 and was replaced by the Ref 16750. It was one of the longest running Rolex references. It was in stainless steel and had the famous Pepsi (red and blue) bezel. The crystal was acrylic because it was made before the era of sapphire crystals. The crystal was identified as the Cyclope 116. There was an additional tropic crytal without a cyclope that was referred to as the Tropic 38.

Unlike its predecessor, the 1675 featured a crown guard. It had pointed crown guards alongside chapter ring gilt dials, until sometime around 1965-66. These pointed crown guards were named named "El Cornino" by collectors for its horn-like appearance. The pointed crown guard was replaced with a more conventional, rounded crown guard that has continued in all GMT and GMT II models.

Here's a pic of the pointed crown guards:



The 1675 also included a new dial inscription that read "Superlative Chronometer Officially Certified."

The original 1675 had a small GMT-hand. In the late 1960s, that switched to a large GMT-hand.

Here's a pic of a small GMT-hand:



There were multiple variations available.

• The Ref 1675/8 was a gold version, available with leather, oyster or jubilee.
• The Ref 1675/3 was steel/gold, available with oyster or jubilee bracelet.
• A version with a brown dial and brown bezel insert was known as the "Root Beer" or "Clint Eastwood". A quick way to distinguish a 1675 Root Beer from the 16750 version is that the 1675 has a nipple dial (cone shaped markers with luminous dots in the center), while the 16750 Root Beers have the more recognizable markers found on other Rolex sports watches.
• In the early 1970s, an all black version was introduced.
• A limited number of blue bezel versions were produced, known as the "Blueberry"

The 1675 was never sold with the red/black ("Coke") bezel. That color combo first appeared on a GMT in 1983, on the GMT II 16760.

The hands are in the following order: GMT/Hour/Minute/Second.

From 1959 until 1964, the movement was a Caliber 1565, and included a gilt dial. The 1565 was marked 1560 on the auto winder bridge.

From 1965 to 1980, the movement was a Caliber 1575 and dial was black matte with white fonts and markings. The 1575 was marked 1570 on the auto winder bridge.

Early versions had a golden Rolex crown on the dial. Later versions had an imprinted crown.

Somewhere in the middle of the two decades of production, a "radial dial" version was used. This dial used smaller hour markers that appear to be further away from the second hashes.

Here's a pic of a radial dial:



Here's a Ref 1675 from 1968 (matte dial). The indexes and hands have aged over time.




Here's a GMT 1675/8 (solid gold) with a brown nipple dial. The "nipple dial" name refers to the specific shape of hour indexes that was only found on yellow gold and two-tone sports Rolex watches in the 1970s and 1980s.



Here's a 1675/3. The use of two-toned gold yellow gold and stainless steel was called "Rolesor" by Rolex. This one also has the nipple dial. It also shows has a black glossy gilt dial with a golden Rolex logo crown at 12 o'clock rather than the printed crowns used in later models.



A black dial 1675:



The "Blueberry" is a rare version of the 1675. It features a rare all-blue bezel and an all-red GMT hand. Most of these bezels were used for special orders in the 1970s.



Here are some movement pics from a 1960 1675:

 

[PlanetZoom]

GMT 16750

Production Period: 1981-1988
Model Name: Rolex GMT Master
Caliber: 3075, 28800A/h, hacking, quickset
Pressure proof to 100m/330ft
Bracelet: Oyster 78360, Jubilee 62510
Glass: Acrylic crystal
Indexes: Tritium

The GMT 16750 replaced the 1675 model. It was replaced by the 16700.

There were many similarities between the 16750 and the 1675. The 16750 included the same acrylic crystal, case dimensions, case back, bezel assembly, bezel inserts and matte dial. However, the dials and hands are not interchangeable between the two models.

The 16750 came with a caliber 3075 movement, which included a quick-set date feature. This feature allows the date to be set independently of the hour hand, a very practical feature. Although the hands have the same appearance as on the 1675, the hand stack was changed. On the 1675, the hand stack was (bottom to top) GMT/Hour/Minute/Second. On the 16750, the hand stack was Hour/GMT/Minute/Second. The hacking feature was standard on all 16750 models.

The early 16750s came with matte dials with white gold indexes like those found on the 1675. In around 1983, the dials were changed to a glossy finish with white gold surround markers.

Just like the 1675, the 24-hour red hand was fixed on the 16750 and could not be set independently. In order to read a second time zone, the wearer had to rotate the bezel/bezel insert and align it with the 24-hour hand.

The 16750 had the same insert as the 1675: the solid black, and the red/blue "Pepsi."

The bezel on the 16750 (same as on the 1675) was rotated by applying downward pressure. The bezel would rate in either direction, and it did not have a click-stop feature like that found on the later sapphire-crystal GMT models.

The 16750 had improved water resistance. It was rated for 300 feet (100 meters), i.e. double the 1675.

The matte dial versions of the 16750 are somewhat rare because they were only produced for about 4-5 years. Also, many matte dials got replaced with glossy dials during servicing.

Other versions included at Ref. 16753: a steel/yellow gold version, available with oyster or jubilee bracelet. Another version was the Ref. 16758 in yellow gold (with leather, oyster, or jubilee).

Here is a 1983 Ref. 16750:



Here is a 1982 16753 with Nipple dial:




Here is a 16758 Root Beer:



A 16758 with a black insert:



Caseback and Movement:

 

[GMTG0D]

Love this!!!

 

[Timnic54]

Great information

 

[PlanetZoom]

Love this!!!

Great information

Thanks, guys, the more I learn about the GMT, the more I like it More to come...

 

[PlanetZoom]

GMT II 16760 aka the "Fat Lady" aka the "Sophia Loren"

Production Period:1983-1988
Model Name: Rolex GMT Master II
Caliber: 3085, 28800A/h, hacking, quickset (24-hour-hand)
Pressure proof to 100m/330ft
Bracelet: Oyster 78360, Jubilé 62510
Glass: Sapphire crystal
Indexes: Tritium

The 16760 is the first GMT II. It was introduced in 1983. In 1988, it was replaced by the 16710.

The GMT II has several differences from the GMT. First off, the watch is larger. It has a thicker case (about .5 mm thicker), a wider bezel, and larger crown guards. This larger design led to its famous nickname, the "Fat Lady." After the 16760 was discontinued, the case was slimmed back down for the GMT 16700 and GMT II 16710 models.

The 16760 is also sometimes called the "Sophia Loren," from comparisons of the curves of the watch to the beautiful Italian actress.

The GMT II was the first watch with the black and red "Coke" bezel. In fact, the 16760 was only available with the red and black bezel and only in stainless steel. Both Oyster and Jubilee bracelets were available.

The 16760 was the first GMT Master equipped with a sapphire crystal All previous GMT watches had less scratch-resistant acrylic (plastic) crystals. These days, all Rolex watches use sapphire crystals.

Another innovation of the 16760 was the dial has 18k white gold around the luminous hour markers, on a black glossy dial. The goal was to prevent tarnishing on the dial. These days, all Rolex watches use 18k gold around the indexes.

The 16760 had a new generation mechanical movement, the Caliber 3085. This movement allowed the center hour hand to be independently set from the arrow tipped 24-hour hand, and also independently from the minute and seconds hands. Thus, when a traveler is in a new time zone, they can easily set the watch to local time simply by moving the center hour hand from one hour to another, without having to move the minute and seconds hand. The same independent hour hand was later used on the GMT II 16750 but not the GMT 16700.

The 16760 was the first GMT to use a rotating bezel that had a click-stop ratcheting feature. The same bezel was later used on the GMT II 16750 and the GMT 16700. The bezel and bezel inserts are interchangeable on all three watches.

The hand stack on the GMT II 16760 is the same as on the GMT 16750: hour (on bottom), 24-hour, minute, seconds.

 

[PACCBET]

Oh mama mia....
The 16750/00 with indices are my grail

 

[PlanetZoom]

GMT 16700

Production Period: 1988-1999
Model Name: Rolex GMT Master
Caliber: 3175, 28800A/h, hacking, quickset (direct)
Pressure proof to 100m/330ft
Bracelet: Oyster 78360 and 78790 (Oysterlock starting 1989), Jubilee 62510
Glass: Sapphire crystal
Power Reserve: 48 hours
Bezel: Bidirectional
Crown: Screwdown Twinlock
Diameter: 40mm
Weight: 123 grams
Indexes:
- Tritum up to U-Series 1997: T<25 dial
- Luminova starting 1998: Swiss dial (variant: Luminova on T<25 dial)

In 1988, the GMT 16750 was replaced by the GMT II 16700, and the GMT II 16760 was replaced by the GMT 16710.

The GMT 16700 was produced from 1998 to around 1999. It was very similar to the 16750. The acrylic (plastic) crystal was replaced with a more scratch-resistant sapphire crystal. The movement was changed to the Caliber 3175, and used the same quick-set feature as was on the 16750. The case was updated, but the case size and appearance were very similar to the GMT 16750 and the GMT II 16710.

There were two available bezels. One was the Blue/Red "Pepsi" (BLRO) (315--16700-6), and the other was the black (LN) (315-16700-1). The rotating bezel was the same as on the GMT II 16760 and 16710, including the ratcheting click-stops and the ability to move either clockwise or counterclockwise. The bezel and bezel inserts on the 16700 are interchangeable with both GMT II 16760 and 16710.

The 16700 was available with only a glossy black dial with white gold surround markers. Initially, the phosphorescence was tritium. Those watches were marked "SWISS - T<25" at the bottom of the dial. In the last few years of production, the phosphorescence was switched to Swiss Luminova. The Swiss Luminova dials were marked "SWISS" on the bottom of the dial.

Starting in 1989, the 16700 included Rolex Oysterlock technology, designed to prevent accidental opening of the clasp.

The GMT 16700 was produced in smaller quantities than its new GMT II 16710 counterpart, and was sold at a lower price.

The last 16700 marked the end of the GMT. Rolex continued to produce only the GMT II.

 

[PlanetZoom]

GMT II 16710

Production Period: 1989-2007
Model Name: Rolex GMT Master II
Caliber: 3185 (late models with 3186), 28800A/h, hacking, quickset (24-hour-hand)
Pressure proof to 100m/330ft
Bracelet: Oyster 78360 and 78790 (Oysterlock), Jubilee 62510
Glass: Sapphire crystal
Bezel: Anodized aluminum, 120 clicks
Indexes:
- Tritium (until 1997): T<25 dial
- Luminova (1998/99): Swiss dial
- Superluminova (2000-2007): Swiss made dial
Hand stack: Hour, GMT, Minute, Second

In 1988, the GMT II 16760 was replaced by the GMT II 16710, and the GMT 16750 was replaced by the GMT 16700.

The GMT II 16710 was produced from 1989 to 2007, when it was replaced by the GMT II 116710. The 16710 was similar in appearance to the 16760 that it replaced. The most noticeable change was the case. No longer a "Fat Lady," the 16710 had a thinner case. Rolex used the same case size for the 16710 and the 16700.

The GMT II 16710 featured the Caliber 3185 movement, which replaced the Caliber 3085 from the 16760. Both movements functioned the same way. They shared the same semi-quick set function and an independent moving hour hand.

The bezel is the same as on the GMT II 16760 and GMT 16700, and is interchangeable between these three models. It includes a
ratcheting click-stop feature and can be rotated in either direction.

Three bezel inserts were available:
1) the red/blue "Pepsi" (BLRO) (315-16700-6)
2) the red/black "Coke" (315-16760-7)
3) a solid black (LN) (315-16700-1)

The 16710 was available with only a black glossy dial and white gold surround markers. Initially, the dial had tritium phosphorescence and was marked SWISS - T25 at the bottom. In around 1998, the phosphorescence was changed to luminova for about one or two years. Those dials are marked SWISS on the bottom. In about 1999, the dials included Super Luminova dials that were marked SWISS MADE at the bottom. The Super Luminova dial was used until the end of production of the watch.

Evolution:

• Tritium -> Luminova -> Super Luminova
• 2000: Sold end link bracelet (SEL)
• 2003: Laser crown
• 2003: No holds case
• 2007: Caliber 3186 instead of 3185

There were two available variations:

• 16713: steel/yellow gold (aka Eye of the Tiger)
• 16718: yellow gold

Comparing the GMT 16700 and the GMT II 16710 is somewhat difficult, as the watches are very close in looks and function. Functionally, the 16700 has a quick set date feature (versus semi-quick on the 16710), while the 16710 has the hour hand that can be independently set. The newer 16710 watches offer Super Luminova.









The 16713:



16718:



Coke:

 

[PlanetZoom]

GMT II 16710 Variations / Anomalies

We all want different levels of perfection in reps. But those have been around know that even gens have variations, font changes, imperfections, and anomalies. Here are some anomalies on the GMT II 16710. The information was compiled from various sources on the internet.

There are variations on the dial of the Roman II. Some have "sticks" for "II" instead of Roman numerals.

Here's a photo showing the difference in the II, and also the size of "Swiss Made"


Z77XXXX - 3185 Rectangular II
Z87XXXX - 3186 Rectangular II
Z96XXXX - 3186 Stick II
M23XXXX - 3186 Stick II
M23XXXX - 3186 Rectangular II
M30XXXX - 3186 Stick II
M36XXXX - 3186 Stick II

There are other differences as well. For example:

• Other fonts have differences
• "-" is shifted to one side on Rectangular II
• "Oyster Perpetual Date" has larger spacing in between on Rectangular II
• "Swiss Made" is smaller on Rectangular II
• The rim on hour markers are thicker on Stick II

Here are some more photos of some variations.

Different II and shift in "-":



Difference in spacing and line weight, and II, and "-":








"Oyster Perpetual Date" spacing is wider:

 

[PlanetZoom]

How to Determine a Caliber 3185 from 3186 through Crown Rotation

One method for determining whether a GMT has a Caliber 3185 or 3186 movement is through the Crown Rotation Method. This method is a way to discern the type of movement without having to remove the caseback. Because the calendar and hour-hand setting mechanism was redesigned in the 3186 movement, the number of turns of the crown to turn the 12 hour hand is different on a 3186 than it is on a 3185.

To perform this test, unscrew the crown such that the crown is in the hand setting position. With the crown face-up, count how many hours the hour-hand travels with one full revolution of the winding crown.

3185: one complete crown revolution makes the hour hand jumps 6 timezones/hours
3186: one complete crown revolution equals 8-9 timezones/hours

 

[JackJ1980]

This is awesome! Thanks man and great info

 

[PlanetZoom]

GMT II 116710

Production Period: 2007-present
Model Name: GMT Master II
Caliber: 3186, 28800A/h, hacking, quickset (24-hour-hand)
Pressure proof to 100m/330ft
Bracelet: Oyster 78200
Glass: Sapphire crystal
Indexes: Super Luminova
Hand stack: Hour, 24-hour, Minute, Second

The GMT II 116710 is a redesigned GMT II. It was introduced in 2007, replacing the GMT II 16710, but it's history actually started earlier. The first reference of this redesigned GMT II was introduced as an anniversary model in 2005 as the Ref. 116718 (now 116718), which was made in yellow gold and had a green dial.




In 2006, Rolex released the steel/gold two-tone version as the Ref. 116713 LN (Lunette Noir).



The new GMT II really caught wind when the 116710 LN was introduced in 2007. The watch has many differences from the 16710.

- The case was redesigned. Still measuring 40 mm in diameter, it had larger lugs and crown guard. The Triplock crown replaced the Twinlock crown. The width of the case (edge to end of crown) is 44.4 mm on the 116710 and 42.45 mm on the 16710. The length (lug tip to tip) is 47.8 mm on the 116710 and 47.5 mm on the 16710. The
changes to the case (and dial--see next point) make the 40 mm 116710 appear larger than the 40 mm 16710. The 116710 is also heavier and a bit thicker (about 1 mm).

- The dial became a "maxi dial," which has wider hands and larger numerals. The red GMT hand was replaced with a green one. If a Rolex has a green hand, that means the watch model is more than 50 years old.

- The aluminum bezel was replaced with a ceramic bezel. Because the bezel is ceramic, this model is sometimes called the GMT IIc. The bezel is the Rolex-patented Cerachrom ceramic bezel, which is highly resistant to scratching and fading. The Cerachrom could not be produced with two colors, however, which is why the six digit GMT Master II was introduced in the black bezel (LN) version. The ceramic bezel has 24 clicks instead of 120.

- The bracelet uses the Easylink system that enables the wearer to widen or tighten the bracelet by 5 mm. Also, the bracelet has polished center links, which gives the watch a shinier appearance. The bracelet attaches using the Oysterlock folding clasp.

- Both the 116710 and 16710 have a sapphire crystal, but the 116710 has anti-reflective coating under the cyclops.

This pic shows the 16710 on the left and the 116710 on the right. You can see how the cyclops reflects light between the two models.




In 2013, Rolex first introduced a two-color Cerachrom as the Ref. 116710BLNR ("Bleu Noir" -- French for blue and black) aka "Batman". This was a major breakthrough. Up until that time, it was considered impossible to create a two-color Cerachrom bezel.



A 116710 LN:



Variations:

- Ref. 116710LN steel with black bezel
- Ref. 116710BLNR steel with black/blue "Batman" insert, blue GMT hand
- Ref. 116713LN steel/yellow gold
- Ref. 116718LN yellow gold
- Ref. 116719BLRO white gold with red/blue "Pepsi" insert, red GMT hand
- Ref. 116758SA yellow gold with diamonds and blue sapphires
- Ref. 116758SARU diamonds, sapphires and rubies
- Ref. 116758SANR white gold with diamonds and black sapphires
- Ref. 116769TBR white gold with lots and lots of diamonds (the "Master Ice")

Here's a pic of the Master Ice:



116758 SARU:



116719 BLRO:



116710 BLNR:

 

[PlanetZoom]

GMT II 16710 Bezel Insert Numbers

The part numbers are the first 3 digits. 315 means it's a bezel insert. The next 4 or 5 numbers are the reference number of the watch. The last number is for the color.

Black with white numbers 315-16750-1
Red/Blue with white numbers 315-16750-6
Bronze/Yellow with yellow numbers 315-16753-5
Black with yellow numbers 315-16753-1
Black with yellow numbers 315-16758-1
Bronze with yellow numbers 315-1675-3
Bronze with yellow numbers 315-16758-3
Black with white numbers 315-16760-7
Black with white numbers 315-16700-1
Red/Blue with white numbers 315-16700-6
Bronze/Yellow with yellow numbers 315-16713-5
Black with yellow numbers 315-16718-1
Bronze with yellow numbers 315-16718-3