CharlieUK Posted January 24, 2009 Report Share Posted January 24, 2009 Greetings on this fine cold day! I am looking to try and replace this hideous (it's really not that bad! ) tube on my MBW case. However, I am unsure about the tap that I would. As you can see, the current tube has a different TPI (threads per inch) than the gen style. Our record show a M3 tap with a .35 thread would require a 2.65mm drill for the subs using the 7030 setup. However, all I have been able to find short of a rolex tap online is a M3 x .5. Obviously, this would require a 2.5mm bit. At the local store, I am able to source IRWIN tools, bits, taps etc. The closest tap I can find is the IRWIN tap requiring a #36 bit, which is equal to .1065 inches or 2.70mm. It is labeled as 32 TPI. Do you think this would work, or would I just end up ruining my case!? Is the TPI ever mentioned for rolex tubes? And lastly, I have read some members did NOT have to countersink their case. I am curious as to how the extra lip around the inner tube threading is dealt with than (which I have marked in red.) Any suggestions or experience on this would be greatly appreciated. warm regards, Quote Link to comment Share on other sites More sharing options...
One4adventure Posted January 24, 2009 Report Share Posted January 24, 2009 (edited) Greetings on this fine cold day! I am looking to try and replace this hideous (it's really not that bad! ) tube on my MBW case. However, I am unsure about the tap that I would. As you can see, the current tube has a different TPI (threads per inch) than the gen style. Our record show a M3 tap with a .35 thread would require a 2.65mm drill for the subs using the 7030 setup. However, all I have been able to find short of a rolex tap online is a M3 x .5. Obviously, this would require a 2.5mm bit. At the local store, I am able to source IRWIN tools, bits, taps etc. The closest tap I can find is the IRWIN tap requiring a #36 bit, which is equal to .1065 inches or 2.70mm. It is labeled as 32 TPI. Do you think this would work, or would I just end up ruining my case!? Is the TPI ever mentioned for rolex tubes? And lastly, I have read some members did NOT have to countersink their case. I am curious as to how the extra lip around the inner tube threading is dealt with than (which I have marked in red.) Any suggestions or experience on this would be greatly appreciated. warm regards, TPI is threads per inch and no TPI (Imperial) Tap would be suitable given that the tube would take a metric thread measured in mm of pitch between each thread. The tap should be available from any machine shop supply house. BTW to figure the correct tap drill for a metric thread just subtract the pitch from the diameter. Hope this helps! Chris Edited January 24, 2009 by One4adventure Quote Link to comment Share on other sites More sharing options...
alligoat Posted January 25, 2009 Report Share Posted January 25, 2009 Unless you can find the 3.0mm x .35 tap, you need to break down and just buy the Rolex tap, like from CousinsUK. Sometimes they want to sell you the pair of taps- including the smaller one for the 5.3mm tubes. Or you could go to Jules Borel here in the US and just buy the single tap for around $35. You don't say which MBW you are working on. On my Euromariner, which is an MBW, I removed the old tube and just tapped the hole and installed the new tube. Countersinking is a decision you have to make on your own. I did have to countersink the two noob cases which I put Rolex crowns and tubes in. On older MBW's, when you removed the tube, it was also necessary to redrill the case hole so it was larger, before you tapped it. I made the mistake of not drilling the hole and busted a tap in the case hole- ugly, and a waste of a good case. Quote Link to comment Share on other sites More sharing options...
stilty Posted January 25, 2009 Report Share Posted January 25, 2009 I made the mistake of not drilling the hole and busted a tap in the case hole- ugly, and a waste of a good case. Have you looked into EDM? Try and find a machine shop with an EDM plunge. They will be able to get it out. An electrical pulse will break up the tap. Quote Link to comment Share on other sites More sharing options...
pauluk Posted January 26, 2009 Report Share Posted January 26, 2009 Have you looked into EDM? Try and find a machine shop with an EDM plunge. They will be able to get it out. An electrical pulse will break up the tap. I bought a tap and the correct drill bit last week from a nut and bolt supplier, it cost Quote Link to comment Share on other sites More sharing options...
alligoat Posted January 26, 2009 Report Share Posted January 26, 2009 I bought a tap and the correct drill bit last week from a nut and bolt supplier, it cost Quote Link to comment Share on other sites More sharing options...
HauteHippie Posted January 26, 2009 Report Share Posted January 26, 2009 I would definitely recommend the counter sinking if at all possible. But the problem with some cases tends to be the downward offset of the case tube hole. So you might break through the bottom edge of the case when you do your countersinking. Quote Link to comment Share on other sites More sharing options...
stilty Posted January 26, 2009 Report Share Posted January 26, 2009 Thanks for the heads up on an EDM, stility. Now I just have to find a machine shop! check here for more information: http://www.sparkeroding.co.uk/ Quote Link to comment Share on other sites More sharing options...
CharlieUK Posted January 26, 2009 Author Report Share Posted January 26, 2009 At today's exchange rate, that's the way to go- around $8+ US. If you can find them like that it's definitely cheaper. Thanks for the heads up on an EDM, stility. Now I just have to find a machine shop! Any recommended sites, I don't have any luxuries of such before mentioned machine shops. Quote Link to comment Share on other sites More sharing options...
Tribal Posted January 26, 2009 Report Share Posted January 26, 2009 There is no other option for a 3x3,5mm Case tapping tool. But you don't need really a Rolex tapping tool there are also cheaper Tapping tools with right dimensions. For countersink the Case hole you can take the rounded diamant dremel tool It's much better then to countersink with a drill bit. You all know the bottom of the Case hole is really thin and can damage easily but with the right tool you can do it with no damages. Quote Link to comment Share on other sites More sharing options...
alligoat Posted January 26, 2009 Report Share Posted January 26, 2009 Here's a place in the US- I just googled metric tapping set, 3mm x .35 http://www.victornet.com/cgi-bin/victor/pr...aps:602,902,604 scroll down to 3mm and .35- $5.40 typical size for 3mm is .5mm on the thread pitch. At that price, I'd order a few. Maybe a metric drill bit or two- 2.65mm. Quote Link to comment Share on other sites More sharing options...
One4adventure Posted January 27, 2009 Report Share Posted January 27, 2009 (edited) Here's a place in the US- I just googled metric tapping set, 3mm x .35 http://www.victornet.com/cgi-bin/victor/pr...aps:602,902,604 scroll down to 3mm and .35- $5.40 typical size for 3mm is .5mm on the thread pitch. At that price, I'd order a few. Maybe a metric drill bit or two- 2.65mm. I just had a quick glance at the linked site, as a toolmaker by trade my advise would be spend $20 and buy a proper machine tap, not the cheaper hand tap. These hand taps are real easy to break. You want a HSS machine tap, and a proper tap wrench (starrett make a nice small one but for one use it might be overkill) just avoid a ratcheting handle, tapping something this small requires the work piece in a vice and two steady hands!!! If this is your first tapping this small I would suggest you get a piece of scrap stainless steel to practice with. Good luck!! Edited January 27, 2009 by One4adventure Quote Link to comment Share on other sites More sharing options...
One4adventure Posted January 27, 2009 Report Share Posted January 27, 2009 PS You need a good tapping fluid as well, stainless is really sticky stuff. Quote Link to comment Share on other sites More sharing options...
Logan Posted January 27, 2009 Report Share Posted January 27, 2009 I've posted this before but its worth mentioning here.. Some rolex crown tubes out there are not a 3 x 3.5 thread, In particular those sold some years back by a guy called Ponycar on ebay were designed for retro fitting old cases with worn threads and are in fact over sized. Presumably Rolex had over size taps to clean the threads prior to using them. Ponycar sold a heap of these before anyone really realized what was going on so there are plenty still in circulation. I posted a while back with all the tube diameters if anyone needs more help to identify which you have. Quote Link to comment Share on other sites More sharing options...
pauluk Posted January 27, 2009 Report Share Posted January 27, 2009 charlieuk I am guessing you are in the uk, send me your address and I will send you one of my taps, you just need the tool to fit it into draper do one for a fiver and just take your time going one way then the other its really easy and as for the countersink just get a new drill bit for steel and turn it by hand it takes a bit of time but its a lot safer then a dremel I think I use an 8mm one. Quote Link to comment Share on other sites More sharing options...
CharlieUK Posted January 27, 2009 Author Report Share Posted January 27, 2009 wow, great info in here guys! Thank you tribal for the countersinking ideas. Thanks for the link alligoat! Should I be worried about the tap breaking (even a cheap one) in a properly drilled hole in SS with a lubricant? One4adv, sorry for my lack of knowledge on the subject, but what is the difference between the high speed steel plug tap that alligoat posted and a machine high speed steel tap? Any recommendations for a fluid that is easy to source? I was think along the lines of using a drill but by hand for countersinking, thanks Paul. I also appreciate the offer for the tap, it is most kind, but i am in the CONUS right now. Quote Link to comment Share on other sites More sharing options...
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