# Threading tool - my first



## Norppu (Jul 16, 2018)

I have been making a tool to make gears in the lathe. While making this thing I noticed that I actually do not have a set of tools to make threads - especially internal threads. So I got this idea of making a combination tool that can do both. 

So I took a DDR origin tool steel bar (10 x 10 x 150 mm. Did some slots to accept a carbide bit which then should be silver soldered in place. Used a 3mm thick carbide slitting saw for making the slots. The other end was turned round. Then in the grinder I gave the supporting form for the carbide bits. Actually this was the easy part and it succeeded quite well.

Next step was to silver solder the carbide bits on each end. So far I have learned that the items must be really clean. So I cleaned them quite well. Another thing I have learned is that it is better to put the torch in the vise and then move the work piece by hand. Also, it seems to be better to nip small bits of the silver and place them into critical places in advance. If everything is set up correctly and if there is a suitable amount of silver then the soldering occurs itself when the work piece is warmed. So it did and the result was satisfactory.

Now, the hardest part of all is to grind the carbide bits into 60 degree form. I did this in my lathe. I tried to keep the dust off from the chuck. This succeeded partially. There weas still some dust in the jaws.

All in all I need to sharpen my grinding skills. The tool can be used but it is far from beautiful. This is somewhat frustrating as everything else went as planned. Grinding carbide into exact form is actually quite difficult.


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## Martin W (Jul 16, 2018)

Looks good to me!. I can appreciate the grinding it takes to make a cutting tool.  
Good work.
Cheers
Martin


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## benmychree (Jul 16, 2018)

For most uses, a carbide threading tool is a waste of time and tends to chip much more easily than HSS; there have been very few things in my over 50 years of machine work that were too hard to thread with HSS tools that can be sharpened much more easily than carbide.


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## markba633csi (Jul 17, 2018)

Good job of protecting the lathe, but preferable of course is a dedicated grinder motor
mark


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## Norppu (Jul 17, 2018)

benmychree said:


> <snip> my over 50 years of machine work that were too hard to thread with HSS tools that can be sharpened much more easily than carbide.



So true. HSS is way easier to grind than carbide. It is also a forgiving material. At the moment all my HSS is in broken center drills. I quess I have to get a few bits of this material.

On the other hand grinding a borin bar from HSS can be a real PITA. Would it be possible to brace HSS ?


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