Correct tap for 7mm tube

[Fraist]

I believe the custom tap is the only solution. But it will cost a lot.
I dont know if there is a watchsmith in the forum that have access to a source to buy the tap.
I believe that specialized shops that sell only to professional watchsmiths will be able to offer this tool.

 

[tbandy]

OK here is a company that offers custom made taps and dies https://westportcorp.com/pages/custom-made-taps-dies
I know if we can order like 6 we can get better price count me on 1 and I know many others will be interested

 

[Zeta7]

Nice idea. I just managed to measure the thread with a tool that i found laying around. The thread is 3x0.30
Please check the pictures. Not the best quality but the thread is that.
Does anyone have any picture with a gen tube with a 0.35 pitch to share and compare?

Now you just need to know if it’s a 55 or 60 degree pitch. Buy the proper tool like in the picture I posted, they’re only like $10.
My threading experience is mainly on replacement barrels and those extreme pressures but you need your threads to hold some serious pressure too. You should do it right so you won’t have any issues down stream. This is just basic machining and there’s no reason to complicate things. Just my humble opinion and a nickel’s worth of free advice man.

 

[tbandy]

Now you just need to know if it’s a 55 or 60 degree pitch. Buy the proper tool like in the picture I posted, they’re only like $10.
My threading experience is mainly on replacement barrels and those extreme pressures but you need your threads to hold some serious pressure too. You should do it right so you won’t have any issues down stream. This is just basic machining and there’s no reason to complicate things. Just my humble opinion and a nickel’s worth of free advice man.

You are 100 % correct I have forgot to mention that

 

[galevin]

What amazes me is that tube replacement probably has been done a few hundred times by probably over 50 guys here. Why did it take 3 pages of material to get an answer? Crown/tube misfittings are common, I’ve got one right now causing me problems. Why isn’t this tap more common among the members? you can’t be the only guy that has retapped a case for a crown tube? Totally mystified.

 

[Zeta7]

What amazes me is that tube replacement probably has been done a few hundred times by probably over 50 guys here. Why did it take 3 pages of material to get an answer? Crown/tube misfittings are common, I’ve got one right now causing me problems. Why isn’t this tap more common among the members? you can’t be the only guy that has retapped a case for a crown tube? Totally mystified.

My limited experience with the parts on this market is it’s used by some as a dumping ground. You never know what’s gonna show up. There’s tube and crowns for a dollar or hundreds of dollars. That’s why it best to always check the threads on your part, every time. It sounds crazy but that’s what I do when I’m working on rifles. I don’t skip steps because it’ll eventually bite you in the arse

 

[Fraist]

Now you just need to know if it’s a 55 or 60 degree pitch. Buy the proper tool like in the picture I posted, they’re only like $10.
My threading experience is mainly on replacement barrels and those extreme pressures but you need your threads to hold some serious pressure too. You should do it right so you won’t have any issues down stream. This is just basic machining and there’s no reason to complicate things. Just my humble opinion and a nickel’s worth of free advice man.

It is the 60 degrees pitch. The 55 degrees pitch threads was for imperial threads and was too big.
I will contact the company in Germany and ask the cost for a tap and if the price is reasonable the best will be to sent a gen tube to measure and prepare a correct tap. This is the best solution. These cheap measuring devices from eBay are not so well made for tiny 0.25 0.3 and 0.35 pitch. Or i need to buy an accurate measuring tool for MF threads (fine threads).

 

[tbandy]

M2.97 X 0.3 6H D3 Right Hand Tap

3 Straight Flutes, Bottoming Chamfer, 6 - 8 Degree Hook, HSS, Bright Finish

1.88" OAL, .56" Thread Length, .141" Shank Diameter, .110" Square Across Flats

1 Pc. $191.25

2 Pcs. $123.75/each

3 Pcs. $90.30/each

6 Pcs. $59.60/each

Lead Time 5 - 7 Working Days

 

[tbandy]

Special Taps, Off Standard & Standard Taps | Cheboygan Tap & Tool

 

[Fraist]

M2.97 X 0.3 6H D3 Right Hand Tap

3 Straight Flutes, Bottoming Chamfer, 6 - 8 Degree Hook, HSS, Bright Finish

1.88" OAL, .56" Thread Length, .141" Shank Diameter, .110" Square Across Flats

1 Pc. $191.25

2 Pcs. $123.75/each

3 Pcs. $90.30/each

6 Pcs. $59.60/each

Lead Time 5 - 7 Working Days

If there are more people interested i believe makes sense to place an order.

 

[tbandy]

I already told you count with me !

 

[Karbon74]

nice

 

[Karbon74]

What amazes me is that tube replacement probably has been done a few hundred times by probably over 50 guys here. Why did it take 3 pages of material to get an answer? Crown/tube misfittings are common, I’ve got one right now causing me problems. Why isn’t this tap more common among the members? you can’t be the only guy that has retapped a case for a crown tube? Totally mystified.

The thing is that thread tolerances are about 10% of the pitch

https://www.accu.co.uk/p/134-iso-metric-thread-tolerances

Most of the modders have successfully used a M3x0.35 but that said, most will use Athaya crowns. So between the tube and tap, it just fits.

 

[Zeta7]

It is the 60 degrees pitch. The 55 degrees pitch threads was for imperial threads and was too big.
I will contact the company in Germany and ask the cost for a tap and if the price is reasonable the best will be to sent a gen tube to measure and prepare a correct tap. This is the best solution. These cheap measuring devices from eBay are not so well made for tiny 0.25 0.3 and 0.35 pitch. Or i need to buy an accurate measuring tool for MF threads (fine threads).

You can get Starrett no.4 gauge for about $20 and they’re top shelf. Is this for a 18k gen crown?

 

[tbandy]

Well like Karbon74 just said, the best thing to do is get a nice gauge just to make sure before placing any order
That way we will make sure to order the right one.

 

[tbandy]

Those are offered by Amazon
Not the best but works.

https://www.amazon.com/Measure-Stainless-America-British-Whitworth/dp/B08VDFM17S/ref=sr_1_10?dib=eyJ2IjoiMSJ9.uxFikhI0lDdxVnTUutXebxi7jWxsXd_GY05PAOf5LCJ6etkWArnJCgc2cbZ1lDK6wQq47dAtRlJI5xj_PJLiOUIw07ZkhFXhk_io7Tp-EwmYr6NGc6Xtba55sY_89R-6dRCooNAnFwncrJyWsJefJgvtmq2fbl3PRnhEUnKz2r9Ffe_uhfwrA3q1InQ4aWZc0yzJI75_f1MOqCSfNYy7OvwkzYXKuqKvGMtXLnwts90.JrvNHly95ZpxpvZ1wMWReXHNlN-oWbIYEQRsVLcTtfg&dib_tag=se&hvadid=580671347969&hvdev=c&hvlocphy=9051798&hvnetw=g&hvqmt=e&hvrand=5508304932630508379&hvtargid=kwd-3211745287&hydadcr=8429_13498140&keywords=thread+gauges&qid=1715532091&sr=8-10

 

[Radiomir369]

I already told you count with me !

Me too!

 

[tbandy]

@Fraist, get in touch with those guys for the custom made taps and let us know how it goes
I think at least 6 taps to get good price so @Radiomir369 wants one, you as the first and me
We have already 3, I bet there will be more that 3 that wants that taps.
If you encounter any problem ordering cuz you are in Germany, let me know I can handle that
Just let me know.

 

[Fraist]

@Fraist, get in touch with those guys for the custom made taps and let us know how it goes
I think at least 6 taps to get good price so @Radiomir369 wants one, you as the first and me
We have already 3, I bet there will be more that 3 that wants that taps.
If you encounter any problem ordering cuz you are in Germany, let me know I can handle that
Just let me know.

It is difficult from me to make a big order from US. I will try to find someone in EU.
If you can organize the US order then I am in.

 

[Karbon74]

It is difficult from me to make a big order from US. I will try to find someone in EU.
If you can organize the US order then I am in.

This provider is german

Rebell | Custom-made tools - taps and dies

www.rebell-tools.de