The Rolex Forums   The Rolex Watch

ROLEXROLEXROLEXROLEXROLEXROLEXROLEXROLEXROLEXROLEXROLEXROLEX


Go Back   Rolex Forums - Rolex Watch Forum > Rolex & Tudor Watch Topics > Rolex Reference Library

Reply
 
Thread Tools Display Modes
Old 22 July 2009, 04:53 AM   #1
Tools
TRF Moderator & 2024 Patron
 
Tools's Avatar
 
Join Date: May 2007
Real Name: Larry
Location: Mojave Desert
Watch: GMT's
Posts: 42,991
Why The GMT IIc Is Not As Waterproof As The Sub !!

Water resistance, and the differences between different Rolex Oyster cases - it's all about the caseback.

Keeping in mind that cases are stamped from a solid piece of 904L Stainless Steel, and the center is also stamped out, concurrently, then the center stamp is further machined to become the caseback for it’s corresponding shell.

The cases of the Submariner (14060, 16610), the GMT II (16710, 116710), and the Explorer II (16570) are all generally the same. The difference is the cut out for the crown – with Triplock for the Submariner and GMT IIc, and Twinlock for the GMT/Explorer II, and final machining at the lugs for shape, and front and back sealing, rehaut, and bezel surfaces. They all share the same 2 mm thick crystal, as well as the crystal and caseback gaskets. The Triplock crown is designed to take 500 bars of pressure, and even though the Twinlock is not as massive, it can take an enormous pressure. When it comes to these models capabilities to take pressure, the real difference is the caseback. The Submariners have a thicker caseback at a respectable 1.51 mm compared to the ~ 0.75 - 0.90 mm of the GMT II/Explorer II. This difference becomes the weak point when handling pressure.

Regarding the GMT IIc, the watch itself has a thicker initial case size than the 16710, but looking at the case-back, it is much flatter against the case rather than being slightly “bubbled out” like the earlier GMT’s and the Sub. This gives the GMT IIc an assembled thickness of ~12mm, almost the same as a 16710 (11.95mm), whereas the Sub 16610 is still thicker at ~13mm, and the 14060M at 12.20mm (thinner non-date movement).

If you apply some rudimentary materials science on the crystal (at what pressure will the crystal crack), and on the caseback (at what pressure is deflection sufficient that the caseback touches the rotor) you will find that the Submariner is good for much more than its rated capability. In fact the caseback is so over-engineered that its margin is much more than twice the rated depth.

Now, since the only real differences between those models are the crown (which is not really the weak point at all) and the caseback; it is fair to say that the pressure capability of the Explorer II and the GMT II depends on the caseback. And even though the case back is roughly half the thickness of the Submariners it is likely still good for a much higher pressure than the rated 100 meters.

It is also worth noting that all 36mm and 40mm models share the same 2mm thick crystal (with the exception of the Sea-Dweller). The 36mm models also have the same thickness of the caseback as the GMT II/Explorer II.

Here are some actual measurements of case back thickness provided by Vanessa and taken by me using a Vernier micrometer and converting to mm:

GMT Master 16750 - 0.72mm
Explorer II 16570 - 0.90mm
Daytona 116520 - 0.96mm
Submariner 16610 - 1.51mm (more than twice the thickness of the old GMT)
Lady's DJ (older) 69174 - 0.50mm
Lady's DJ (newer) 79174 - 0.49mm
Gent's DJ (older) 16013 - 0.75mm
Gent's DJ (newer) 16233 - 0.81mm


Given this simple reasoning it should be easy to see that any Rolex Oyster is capable of taking a pressure much higher than its rating, and much more than any recreational diver will ever go down to. If you do an annual pressure test, or at least every two years, of your Rolex you can go diving with any model.

Of course, the Triplock offers better safety when it comes to leakage through the crown. But what one seldom thinks about is the fact that there is still only one gasket between the crown tube, and the case.

By the way: All models are tested by Rolex to 125% of their rated capability.

This is what Rolex themselves said in an ad for the Acrylic crystal models, and since the only difference now is the material, and even better gaskets the facts should still apply. (Let’s assume that Rolex did use real facts in this test.)

............................................................................................

Contributors:
acce1999
Vanessa
Ironstark
__________________
(Chill ... It's just a watch Forum.....)
NAWCC Member
Tools is offline   Reply With Quote
Old 26 July 2009, 02:12 AM   #2
Orchi
Banned
 
Join Date: Dec 2007
Location: Malaysia
Posts: 2,934
Err buddy Larry...thanks for sharing your excellence findings...
Orchi is offline   Reply With Quote
Old 3 August 2009, 03:22 AM   #3
YuppieKid
"TRF" Member
 
YuppieKid's Avatar
 
Join Date: Sep 2007
Real Name: Brandon
Location: West Coast, US
Posts: 1,079
As usual, a fine and >>

educational read.
YuppieKid is offline   Reply With Quote
Old 4 August 2009, 12:10 AM   #4
Deeper
Member
 
Join Date: Apr 2009
Location: Denmark
Posts: 62
This is great info. Thanks!
Deeper is offline   Reply With Quote
Old 9 August 2009, 11:01 AM   #5
Perdu
"TRF" Member
 
Perdu's Avatar
 
Join Date: Jul 2007
Real Name: Gary
Location: GMT-6
Watch: GMT
Posts: 3,350
Excellent read and thank goodness the measurements are in mm. Fractions of an inch confuse me totally.
__________________
Omega Seamaster 300M GMT Noire
Omega Seamaster Aqua Terra 8500

Benson 1937 Sterling Silver Hunter
Perdu is offline   Reply With Quote
Old 9 August 2009, 11:12 AM   #6
Flaxmoore
Member
 
Join Date: Dec 2008
Real Name: Casey
Location: Toledo, Ohio
Watch: Alpha Milsub
Posts: 704
Quote:
Originally Posted by Tools View Post
The Triplock crown is designed to take 500 bars of pressure, and even though the Twinlock is not as massive, it can take an enormous pressure.
500 bar? You mean 5000 meters or 17,000 feet? Whoa.
Flaxmoore is offline   Reply With Quote
Old 17 August 2009, 12:13 AM   #7
rimakis
Member
 
Join Date: May 2009
Location: New Jersey
Posts: 18
Would it be possible to swich out a twinlock on the old GMT and put in a triplock?

George
rimakis is offline   Reply With Quote
Old 27 August 2009, 07:50 AM   #8
HYDROMAROC
"TRF" Member
 
HYDROMAROC's Avatar
 
Join Date: Aug 2007
Location: SAN DIEGO, CA USA
Watch: me pass...
Posts: 1,111
I like the price on the right hand side... Can't make out the one for the SS but the gold version looks like $1400.00 in 1972...
HYDROMAROC is offline   Reply With Quote
Old 27 August 2009, 08:43 AM   #9
plat-numb
Member
 
Join Date: Jun 2009
Location: TN
Posts: 47
What are the differences in the 16610's and a 16622?

They are rated @ 300 and 100... But have the same 3135 movement and a trip lock crown?

Curious as to what your thoughts on this are.
plat-numb is offline   Reply With Quote
Old 4 September 2009, 05:00 PM   #10
Dreamer
"TRF" Member
 
Join Date: Aug 2009
Location: Australia
Watch: too many to name
Posts: 8
Thanks , great explanation.

Dreamer is offline   Reply With Quote
Old 10 September 2009, 09:59 AM   #11
iberjan
"TRF" Member
 
Join Date: Aug 2009
Location: New York City
Watch: Rolex green sub
Posts: 25
I was wondering about that. Thank you.
iberjan is offline   Reply With Quote
Old 11 September 2009, 06:55 AM   #12
rmcarlton
"TRF" Member
 
rmcarlton's Avatar
 
Join Date: Oct 2007
Real Name: Monty
Location: Georgia
Watch: Sub LV
Posts: 787
Thanks, Larry for the info! Good stuff.
rmcarlton is offline   Reply With Quote
Old 11 September 2009, 09:57 AM   #13
drefrank
2024 Pledge Member
 
drefrank's Avatar
 
Join Date: Sep 2009
Location: New Hampshire
Posts: 910
Great info. I've got a bit more respect for my Sub after reading the above.
drefrank is online now   Reply With Quote
Old 12 September 2009, 02:46 PM   #14
icnbne
"TRF" Member
 
icnbne's Avatar
 
Join Date: Apr 2009
Real Name: J
Location: Brisbane
Watch: Rolex Omega Seiko
Posts: 1,562
great read mate, thanks for the education
icnbne is offline   Reply With Quote
Old 28 September 2009, 08:47 PM   #15
miamiman
"TRF" Member
 
miamiman's Avatar
 
Join Date: Sep 2009
Real Name: wil
Location: miami,fl
Watch: rolex 1675
Posts: 146
would that crystal have shattered if it was glass instead of acrylic when they did the pressure test .???
miamiman is offline   Reply With Quote
Old 29 September 2009, 03:04 AM   #16
JJ Irani
Fondly Remembered
 
JJ Irani's Avatar
 
Join Date: May 2005
Real Name: JJ
Location: Auckland, NZ
Watch: ALL SOLD!!
Posts: 74,320
Bravo, Larry......the above is absolutely top class information!!

Would you happen to know the actual thickness of the GMT-IIC caseback? And, if so, would it be safe for me to assume that the YG caseback of the GMT-IIC would have the same thickness as the SS one?

Many thanks - JJ
__________________
Words fail me in expressing my utmost thanks to ALL of you for this wonderful support during my hour of need!!

I firmly believe that my time on planet earth is NOT yet up!! I shall fight this to the very end.......and WIN!!
JJ Irani is offline   Reply With Quote
Old 29 September 2009, 03:15 AM   #17
cody p
"TRF" Member
 
Join Date: Jun 2008
Location: Canada
Watch: Air-King 114200
Posts: 2,878
good to know.
cody p is offline   Reply With Quote
Old 1 October 2009, 01:14 AM   #18
JBat
"TRF" Member
 
JBat's Avatar
 
Join Date: Dec 2007
Real Name: John
Location: Washington
Watch: 16710, 16610, DJ
Posts: 7,329
Great info, Larry, and very interesting.
JBat is offline   Reply With Quote
Old 1 October 2009, 04:34 AM   #19
bandityo
"TRF" Member
 
bandityo's Avatar
 
Join Date: Sep 2009
Location: Chattanooga
Watch: Rolex Submariner
Posts: 129
yes thank!

david
bandityo is offline   Reply With Quote
Old 1 October 2009, 04:52 AM   #20
Nicko
Banned
 
Join Date: Aug 2009
Location: Not here anymore
Posts: 4,787
Quote:
Originally Posted by HYDROMAROC View Post
I like the price on the right hand side... Can't make out the one for the SS but the gold version looks like $1400.00 in 1972...

Well, I'll tell you, it's definitely less than a Rolex service today!
Nicko is offline   Reply With Quote
Old 13 October 2009, 04:25 PM   #21
fisk
"TRF" Member
 
fisk's Avatar
 
Join Date: Sep 2008
Location: Canada
Posts: 9
Thanks for sharing
fisk is offline   Reply With Quote
Old 26 October 2009, 12:52 PM   #22
Nick1959
"TRF" Member
 
Join Date: Oct 2009
Location: New York
Watch: Rolex DSSD
Posts: 558
Thanks still learning
Nick1959 is offline   Reply With Quote
Old 27 October 2009, 05:26 AM   #23
Alexus
"TRF" Member
 
Alexus's Avatar
 
Join Date: Aug 2007
Real Name: Alex
Location: Switzerland
Watch: SD/PAM74/ExII/SRSD
Posts: 393
thanks for sharing that great info
__________________
The young do not know enough to be prudent, and therefore they attempt the impossible, and achieve it, generation after generation.
Pearl.S.Buck
Alexus is offline   Reply With Quote
Old 3 November 2009, 01:31 AM   #24
inspires
"TRF" Member
 
inspires's Avatar
 
Join Date: Aug 2008
Real Name: Eric
Location: Hong Kong
Watch: 1665
Posts: 1,495
Fantastic info - I always learn something when I log on TRF
__________________
_____________
All GREEN
inspires is offline   Reply With Quote
Old 27 November 2009, 12:11 PM   #25
david6
"TRF" Member
 
Join Date: Nov 2009
Location: Hong Kong
Watch: GMT Master II
Posts: 6
Thanks so very much! Larry and the other contributors
Great learning material from experts.
Could I quote your useful materials in some HK forum to share with other Rolex watch lovers here?
Just let me know and I'll 100% respect your decision.
Cheers
david6 is offline   Reply With Quote
Old 16 December 2009, 12:01 AM   #26
Puffy
"TRF" Member
 
Puffy's Avatar
 
Join Date: Oct 2009
Location: Here and there
Posts: 12,485
Interesting read.
Puffy is offline   Reply With Quote
Old 4 February 2010, 10:39 AM   #27
TheBluePrince
"TRF" Member
 
TheBluePrince's Avatar
 
Join Date: Dec 2009
Location: London
Posts: 2,081
Just read this. Great research and investigation, thanks for sharing.
TheBluePrince is offline   Reply With Quote
Old 7 February 2010, 05:21 AM   #28
dama156
"TRF" Member
 
dama156's Avatar
 
Join Date: Jan 2010
Real Name: David
Location: Long Island, NY
Watch: gmt c
Posts: 130
great info< thanks
dama156 is online now   Reply With Quote
Old 11 February 2010, 11:04 PM   #29
brae2009
"TRF" Member
 
Join Date: Jan 2010
Location: egy
Posts: 3
nice man keep going
brae2009 is offline   Reply With Quote
Old 12 February 2010, 12:12 AM   #30
Jason Judd
Member
 
Join Date: Jan 2010
Real Name: Jason
Location: ny
Posts: 27
And that's why I'm gonna' get a Sub!
Jason Judd is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Takuya Watches

Bobs Watches

Asset Appeal

My Watch LLC

OCWatches

DavidSW Watches

Coronet


*Banners Of The Month*
This space is provided to horological resources.





Copyright ©2004-2024, The Rolex Forums. All Rights Reserved.

ROLEXROLEXROLEXROLEXROLEXROLEXROLEXROLEXROLEXROLEXROLEXROLEX

Rolex is a registered trademark of ROLEX USA. The Rolex Forums is not affiliated with ROLEX USA in any way.