# Threading tool from drill rod.



## David Kirtley (Jan 20, 2014)

Decided to make me a little threading tool to use for internal threads (Well, external too as you will see.)

I started out with some 1/2in diameter W1 drill rod. Why W1?  Because it was sitting next to my lathe, fit the boring bar holder, it was already cut off at a usable length, and I didn't feel like looking for my O1.

I cut a relief of about 1/8 or so (Now that I think about it, I never measured it as it didn't really matter.) I then set the compound to get a 60 degree included angle. I turned one side forward and then put it in reverse to cut on the back side so I didn't need to readjust the compound.

Stuck it in a boring bar holder and put a 1/2 in endmill in the lathe spindle and milled 1/2 of it off (well, a bit more than half to give me some clearance angle.)




I hardened it and tempered to a light straw color. Finally took my handy push button torch out of the package where it has lived ever since I brought it home. The gas was MAPP gas but propane would have worked just as well. I had bought the MAPP for some brazing.




Here is what it looks like on the other side.




Then I made a few test cuts on some aluminum. It cuts quite well and leaves a nice finish.




The top angle is just the radius of the 8in wet grinder I used to sharpen it.  It cuts quite cleanly and I am really happy with it.  I will make some more of different sizes and one cut on the back side to be able to get into smaller bores.  I think I will also make one for 1/2-10 Acme so I can get a bit tighter tolerances than I get with the tap.  I will also make myself a few counterbores for cap screws.


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## xalky (Jan 20, 2014)

Let us know how it holds up threading mild steel. Nice job. )))


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## Kevinb71 (Jan 20, 2014)

It's nice to know there's always another way to do that. Good idea!


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## Kevino (Jan 22, 2014)

Good idea, thanks for sharing.


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## Walltoddj (Jan 22, 2014)

Looks like it will be easy to sharpen as well, great idea and cheap to make! I have a tool I made in my apprenticeship that works great on a surface grinder take longer to start the grind than to sharpen the tool.


Todd


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## David Kirtley (Jan 22, 2014)

xalky said:


> Let us know how it holds up threading mild steel. Nice job. )))



I do know that it will work fine though. Not that long ago, all metal was cut with carbon steel cutters. They just had to sharpen more often.  I tried it and it didn't leave a good finish on the mystery steel scrap I had handy.  A bit more honing would have helped but I really didn't worry as I will be mostly using this cutter on aluminum and plastics.  I put in an order for some silver solder to make some tools with HSS and carbide tips. Then I can make the holders out of 12L14 that is much easier on my poor little lathe. The W1 needs quite a bit of tool pressure to cut well. For some odd reason, my nice A.R. Warner HSS inserts had problems with the W1 but I switched over to carbide inserts and it was much happier. I would have expected the opposite.


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## jocat54 (Jan 22, 2014)

Thanks for posting this.

I have several made from O1 and they work great-----at least for me cutting mostly mild steel and aluminum. Don't use them real often but work good when I have used them.


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## jocat54 (Feb 9, 2014)

I was making a acme threaded rod (5/8 x 8tpi) and needed to cut some internal threads for a nut to fit the shaft so I wondered if this tool would work for the acme threads. So I made one and I was worried about the amount of material it had to cut with the flat nose.  It does quite nice if you go slow enough) and keep the shank short.


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## David Kirtley (Feb 9, 2014)

Cool.  I have partially made one for Acme threads but have not ground it down yet. Wish I had done it before I spent the bucks on the Acme tap.

I am thinking about trying with HSS. I might need to do it with a grinder rather than just carbide tooling though. Just guessing as I have never tried turning HSS.


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## Rangerjoe2 (Nov 26, 2014)

I made one awhile too.  I really like it for internal threading.  Spin the lathe in reverse, fed from left to right and hold on.  It's great for blind holes.  You don't need to worry about crashing the tool bit.  I like it so much I bought a carbide left handed threading tool.


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