dbane883 Posted June 16, 2015 Report Share Posted June 16, 2015 Ok, I will begin by saying that very few may appreciate my findings below as I'm sure it would be fairly boring for most. You have been fairly warned. So, if you have ever installed a genuine 8mm (800-0), you may agree with me that they are a $#@$^ to install. The common intel in the past has suggested to us that the correct tap for the big crown tubes are M4x0.35, The M4 designation is the diameter (in mm) and the 0.35 is the spacing of the threads. This is the tap that is recommended by Adrian for his 8mm tubes and what I always believed was the correct tap for genuine tubes. But after tapping, the 800-0 tube just doesn't seem to go in much more than a few threads... There's a couple of reasons for this. First of all, the M4 taps are not exactly 4.0mm.. they are about 3.9-3.95mm. If you measure the 800-0 tube, its about 4.0-4.1mm.. Not a big difference but it can be a pain in the ass when trying to screw it in with a triangular/square file. This is often the case with other tube like the 702-0.. A solution then is to lightly sand down the threads of tube until if fits nicely.. its a pain, but it has to be done. I know that Phong also taps his 6538 cases with M4x0.35 as well. But last week, I was browsing around and found NOS Rolex taps specifically for the 800 tubes. When I received it in the mail today (it was NOT cheap), lo and behold, i looked at the tap size etched on the side. M3.9/4.1x0.30 !! WTF? yes.. WTF. I dont have calipers with me at the office here, but I suspect the actual dimension is a touch wider than normal M4 taps. I would imagine the designation implies that the teeth width is 4.1mm and the teeth depth diameter is 3.9. Also, the pitch is different.. That too would have caused issues with instalment using an M4x0.35 tap as the threads on the tube must be a hair closer together. I will admit, there were times early on when I thought it was me.."Maybe I'm the only one that's ever had an issue with installing a gen tube".. But after having installed about a dozen now, I always suspected that there must be a proprietary tap that Rolex uses.. and now that suspicion has been confirmed. I don't believe I've every seen a M4x0.30 tap let alone a M3.9/4.1x0.30. Anyhow, just thought I'd let you know. Oh, I also pick up a proper 8mm tube wrench tip and the proper tube "reemer". No more using cylindrical files! 1 Quote Link to comment Share on other sites More sharing options...
alligoat Posted June 16, 2015 Report Share Posted June 16, 2015 Thanks for sharing! This is probably a dying art form since the 6538 hasn't been made in over 55 years and Rolex probably wouldn't touch one at this point in time. I put a 7020 tube in a cartel 5513 case last night. The 3mm x .35 tap left a slightly too big hole in the case- resorted to epoxy- never a victory when you resort to epoxy! Guess I could have gone with the 7030 tube, but I wanted the 702 crown look. Quote Link to comment Share on other sites More sharing options...
Nanuq Posted June 16, 2015 Report Share Posted June 16, 2015 Yep. Usually when something will thread 2 turns or so, it's a thread pitch problem, not thread diameter. Great write up! Quote Link to comment Share on other sites More sharing options...
pam007 Posted June 16, 2015 Report Share Posted June 16, 2015 Awesome job as always D. I remember I had to lightly sand my 7020 for my 5513 project Damn you Rolex... Damn you... Quote Link to comment Share on other sites More sharing options...
cc33 Posted June 16, 2015 Report Share Posted June 16, 2015 Wow, that's very insightful, those new tools are so cool and obv perfect for the task at hand! Quote Link to comment Share on other sites More sharing options...
jmb Posted June 16, 2015 Report Share Posted June 16, 2015 I recently had to order an M4x.35 tap for the 8mm tubes. Only one I could find had to come out of China... Quote Link to comment Share on other sites More sharing options...
lionsandtigers Posted June 16, 2015 Report Share Posted June 16, 2015 engineer porn? Quote Link to comment Share on other sites More sharing options...
Mendota Explorer Posted June 16, 2015 Report Share Posted June 16, 2015 So what does this mean for those of us embarking on budget big crown builds using Athaya 8mm brevet crowns and tubes? Will the tap that Athaya recommends for his tube actually work with the tube? Quote Link to comment Share on other sites More sharing options...
dbane883 Posted June 16, 2015 Author Report Share Posted June 16, 2015 Yes. A m4x0.35 is perfectly fine for Athaya tubes. Sent from my iPhone using TapatalkAnd a gen crown will fit on a Athaya tube. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Mendota Explorer Posted June 16, 2015 Report Share Posted June 16, 2015 ^ Brilliant. Thanks! Quote Link to comment Share on other sites More sharing options...
Dlf Posted June 17, 2015 Report Share Posted June 17, 2015 Madness, but thanks for sharing!!, Love these threads Quote Link to comment Share on other sites More sharing options...
SSTEEL Posted June 17, 2015 Report Share Posted June 17, 2015 Thanks for clarifying this, as I have had a few head scratching moments myself regarding these 8mm crowns. Quote Link to comment Share on other sites More sharing options...
Kime Posted June 17, 2015 Report Share Posted June 17, 2015 Is the tube wrench the same as the one for the Athaya tube, as I have been yet to find one that fits his tube. Quote Link to comment Share on other sites More sharing options...
dbane883 Posted June 17, 2015 Author Report Share Posted June 17, 2015 I don't think so Kime. The splines on the gen tubes are down on the lower part of the tube shaft. On the Athaya, the internal splines are up near the top in the gasket area. I have a Athaya tube somewhere and will confirm. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Kime Posted June 18, 2015 Report Share Posted June 18, 2015 Thanks, I can believe they are either, I have tried 3 "gen spec" Rolex tube fitting spline tools and none fit. I would love a correct tool and have urged Athaya to update his design but I know he is busy on other projects at the moment. Knowing the correct tools for a gen I'm sure would help him on a redesign. Quote Link to comment Share on other sites More sharing options...
dbane883 Posted June 18, 2015 Author Report Share Posted June 18, 2015 I think for the average person, Adrian's design is fine. If he put the splines in the lower tube shaft ala gen, guys would need to broach/reem the splines off after installation. Not easy to find the right parallel cylindrical files to do this. Filing down the internal teeth is also fraught with peril. It's easy to file away too much and the tube will weaken and snap off because most will probably use a common tapered file which removes too much material from the top portion of the tube relative to the bottom. His design is superior to gen in terms of ease of installation IMO. The gen 8000, 7000, and 7020 tubes all require the same delicate surgery. With the Athaya tubes, they are ready to go after being twisted in. Sure, he could provide a proper tool, but a torx bit usually works fine. Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Kime Posted June 18, 2015 Report Share Posted June 18, 2015 I think for the average person, Adrian's design is fine. If he put the splines in the lower tube shaft ala gen, guys would need to broach/reem the splines off after installation. Not easy to find the right parallel cylindrical files to do this. Filing down the internal teeth is also fraught with peril. It's easy to file away too much and the tube will weaken and snap off because most will probably use a common tapered file which removes too much material from the top portion of the tube relative to the bottom. His design is superior to gen in terms of ease of installation IMO. The gen 8000, 7000, and 7020 tubes all require the same delicate surgery. With the Athaya tubes, they are ready to go after being twisted in. Sure, he could provide a proper tool, but a torx bit usually works fine. Sent from my iPhone using Tapatalk I would be massively greatfull if you can pass on which torx bit because I have tried every size, none fit and 3 different spine tools designed for gen Rolex tubes. Quote Link to comment Share on other sites More sharing options...
Nanuq Posted June 19, 2015 Report Share Posted June 19, 2015 Not easy to find the right parallel cylindrical files to do this Try chainsaw files. Pferd makes the best. Quote Link to comment Share on other sites More sharing options...
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