How to thread stainless

Mine are held in by two bolts only and never caused a problem.
I dont know if its the photo but in the first and third ones It looks as if there is a tiny vertical strip along the top edge, like to get the side relief all the way to the top of the bit.
caveat - I have no formal training the above is what I have found works.
 
FTlatheworks said:
How’s this boys?
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Not quite. There is a gap on the right side and there should be NO gap there. The grind is off angle a bit but that is minor; you just need to align the 60 deg angle so it is dead on perpendicular to the work piece and you use your fishtail for that.

Be sure to hone the two sides and the top and put a small flat at the tip or the tip will crack off; trust me on that.

Two hold down screws will work fine in your tool holder.
 
mikey said:
Not quite. There is a gap on the right side and there should be NO gap there. The grind is off angle a bit but that is minor; you just need to align the 60 deg angle so it is dead on perpendicular to the work piece and you use your fishtail for that.

Be sure to hone the two sides and the top and put a small flat at the tip or the tip will crack off; trust me on that.

Two hold down screws will work fine in your tool holder.
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Yes, the grind isn’t perfect by any means. I have to do it completely free hand. I use the grinder at work. The gap is from me holding my phone and trying to hold the gauge at the same time and being crooked On the tool. It fits snug except my flat spot on the nose of the tool. Should my tool for that rectangle in the end of the gauge perfectly? That’s tough freehand!
 

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There’s my aluminum threads. My major and min diameter came out perfect. Finish was ok, but no burrs.
 
So, need to hone my tool making skills and try SS. Next. After getting the angle perfect and cleaning it up as Mikey suggested.

Nvm, I see the uneven angle on it Mikey. I can see it in the picture.
 
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savarin said:
Mine are held in by two bolts only and never caused a problem.
I dont know if its the photo but in the first and third ones It looks as if there is a tiny vertical strip along the top edge, like to get the side relief all the way to the top of the bit.
caveat - I have no formal training the above is what I have found works.
Click to expand...
I’ll take it any help I can get.
 
FTlatheworks said:
So, need to hone my tool making skills and try SS. Next. After getting the angle perfect and cleaning it up as Mikey suggested.

Nvm, I see the uneven angle on it Mikey. I can see it in the picture.
Click to expand...

Keep in mind that any imperfection of that 60 deg angle will transfer to your thread form so try to get the angles perfect. It just take some time to get it down so stick with it, it will come. Make sure to hone both sides and the top so no grind marks show on your cutting edges, then make that flat.
 
I use those cheap little plastic backed diamond hones, I find they work rather well.
 
savarin said:
I use those cheap little plastic backed diamond hones, I find they work rather well.
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I’m unfamiliar with those, except for the ones in the knife sharpening kits. We have a bevel/table/disc grinder, but I ruin a lot of material way faster with that. It’s basically a large motor attached to a piece of sand paper cut in a circle.
 
I'm a little late to the party here, but I'll throw in my 2 cents anyway. I thread 100's of 304 and 303 parts every month (1/2-20), both internal and external.

Internal is all done with a spiral flute, powered metal Guhring machine tap, designed for SS, and using a 50% thread depth drill.

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External threading is done with an Accusize insert holder. https://accusizetools.com/products/...threading-inserts?_pos=3&_sid=9c18780a2&_ss=r

500 RPM, 5 passes with a finish spring pass. I use a reduced step down strategy where each pass has less depth than the previous and starts at about 0.01 DOC and finishes at about 0.002 DOC. Flood coolant.



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I use these Mitsubishi MMT16IRAG60 VP10MF inserts, designed for SS
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I get a little tearout on the 303 SS, but the 304 SS threads are nice and smooth. I could work with the cutting parameters to clean up the 303 threads a bit, but they meet our needs as they are.

The 304 is much harder on the tools than is 303. I can get a few hundred parts per edge in the 303, where the 304 I get a couple hundred at best.

Also I just received my new Shars threading insert holder today. https://www.shars.com/3-4-mtvo-external-threading-grooving-tool-holder-right-hand

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and these inserts https://www.shars.com/tnmc-32nv-tin-carbide-insert

I bought this because we are changing the design of the parts and need the extra clearance. on the face.
 
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