Rolex 703 crown and tube: Internal spline size

[HSV726]

Hi

I am looking to fit a genuine 703 crown and tube.

I have seen a few different options for the internal spline tool to score the tube into the mid case.
Am I right in thinking that a o3.00mm tool would be correct ?
(the other options are o2.70mm or 3.25mm)

 

[HSV726]

*to screw the tube into the mid case

 

[HSV726]

Just to update for any future searches

I can confirm that the 3.00mm tool is the correct fit.

I purchased the below item

 

[trust_wrx]

thanks buddy, was looking to do the same mod... so i will need a 3mm tool..
any tips on Tapping the case?

 

[HSV726]

Apologies only just seen this,

The tapping itself was fairly straightforward, used my drill press vice to keep the case as flat as possible (pic below), used plenty of cutting fluid and went very slowly, a couple of turns in then backed it out then a few more turns in and so on until the tap had gone right through



I found the countersinking was much more of a challenge, used my drill press with the correct countersink bit, main problem was i wanted to open it up in small increments and test fit the tube along the way unfortunately to get the tube started I had to retap the case I every time I opened up the countersink. Got it done in the end but it took me quite a while

 

[trust_wrx]

thats great!! thanks for sharing.

So now you have fitted the new Crown Tube?
Which was the correct tap?
M3 x 0.35?

Cheers,
Shannon