Counterboring a Rolex case tube

[mp1mancini]

Based on some research I’ve found on getting a gen 7030 case tube to fit properly in a rep case (GMF for my situation).


It looks like tube hole has to be counterbored (as opposed to some generically suggesting countersunk).



What I can’t seem to find is:
1) Proper counterboring bit to do this
2) A convenient way to do it, if I don’t have a jig to hold the case or a drill press.

Maybe first question should be about feasibility...

 

[KJ2020]

I would not attempt this without a drill press bro. And one better than a "table top" one at that. SS is tough stuff to drill into.

 

[mp1mancini]

Good to know, I'm lining one up now.

For all those gen crown/tube sales that go through M to M there must be some that are doing this right or are they just screwing them in and dealing with the gap?

 

[KJ2020]

Good to know, I'm lining one up now.

For all those gen crown/tube sales that go through M to M there must be some that are doing this right or are they just screwing them in and dealing with the gap?

Some cases have the counterbore already, really they all should. I know ARF frequently skips it, that's a well known flaw. Personally I wouldn't introduce a gap like that it counters the principle of adding gen parts, I doubt many people do that.

 

[mp1mancini]

Ah ok, so do the gen crown, then a gen tube if the case is counterbored.

 

[Specter1000]

be very careful if you counterbore or countersink...you can EASILY go to far and the tube will extend too far and go into the case

 

[mp1mancini]

Yeah it looks like not much. Waiting on tube to get actual measurements.

Still trying to decide how to go about it, if I do.

 

[KJ2020]

Yeah it looks like not much. Waiting on tube to get actual measurements.

Still trying to decide how to go about it, if I do.

Plenty of ppl do this, so it's not something you can't learn how to do. One little bore, piece of cake haha. Use a junk case and make a bunch of bores to practice.

 

[mp1mancini]

Ya, I've got a couple of Canal Street specials that I'll be using for practice.

 

[Specter1000]

For a countersink I have used a single flute 45 deg. tool, somewhat slow speed and touch then check. Single flute cuts down on chatter from what I read and it worked perfectly.

 

[KJ2020]

For a countersink I have used a single flute 45 deg. tool, somewhat slow speed and touch then check. Single flute cuts down on chatter from what I read and it worked perfectly.

Beautiful work bro

 

[mp1mancini]

For a countersink I have used a single flute 45 deg. tool, somewhat slow speed and touch then check. Single flute cuts down on chatter from what I read and it worked perfectly.

PERFECT !!!

I’ll try just this way.

Thanks
Specter1000

 

[Specter1000]

Any chance to tell us where did you buy this from ? I was looking and only see 4 flute

 

[mp1mancini]

Ok that's great info. So I started doing a little research and came upon this. Seems crude relative to the work needed on a small case.

https://youtu.be/kk-Yhcvp2Bg

After this video though wondering if a simple cobalt bit would work given how shallow the bore has to be. He had an interesting idea to just slice off the end of a bit making it flat.

The remarks after the video were a good read also.