junbug5150 Posted December 10, 2015 Report Share Posted December 10, 2015 Hi everyone,I just went through tapping a Silix 6538 case to accept Athaya's 8mm Brevet crown. The cases needed to be drilled first and then needed to be tapped to accept the crown. Hope some of you find this usefulTools & Parts:- Silix 5510/6538 case- Rat tail file- Table Vise- Cordless Drill (>7.8volt)- Lubricant for metal cutting- Tap Wrench- 3.5mm Cobalt Drill Bit- M4x0.35mm TapFirst step is to remove the existing tube (look how tiny that Silix tube looks!). I used a rat tail file to grip the inner tube. Once you've got a good grip, simply unscrew counter-clockwise. Voila! Next, you secure the case in the table vise. Lube the hole where the tube was and use the 3.5mm Cobalt drill bit with your cordless drill. I used my 7.8v first, but wasn't as effective so I used my 20v. Had to be patient but wasn't difficult at all. Drill all the way through. Be sure to clean off any burrs. You can use that same rat tail file from earlier. Now you need to put that M4 tap onto the tap wrench. Make sure you get the 0.35mm pitch! 0.7mm are more common, but they won't work! I've purchased mine from Merlintools on Ebay for $12 per. Get a couple while you're at it. I couldn't photograph since both my hands were occupied, but once the tap bites onto the case you do a 1 turn clock-wise and then 1/2 turn counter clock-wise. By going counter clock-wise you're removing the excess steel. Athaya tubes are pretty long so I went all the way through the case. Now you should be able to hand screw that new tube in most of the way. Towards the end I used that rat tail file again to tighten all the way down. NOTE: if you have a choice, use the triangular file. Cone shaped are very difficult to remove from the tube because it bites more area on the tube. And there we go BONUS:So we know 3.5mm Cobalt and an M4x0.35mm tap is needed for the 8mm Brevet Athaya crown and tube.For Rolex Explorer 1016s to accept the 6mm gen crown and tube, you'll need to drill out the case using 0.110" or #35 first and use the M3x0.35mm tap. If you aren't up for it, jmb is your go toTC 16610 to gen tube seems to have the same diameter so drilling doesn't seem necessary. It would use the same tap as the 1016, M3x0.35mm. See here: https://www.replica-watch.info/vb/sh...ll-this-myselfHope this was useful! Good luck! 8 Link to comment Share on other sites More sharing options...
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