internal threading tooling

[yooper]

I have a 13x 40 lathe that I have been learning to use. I am at the point that I would like to try internal threading. What I am looking for is what the folks on here would recommend for a beginner.

 

[xalky]

A boring bar with a hand ground square HSS cutter. That's what you need to get started.

Something like this :

with some of these

ground to a profile like this: http://www.wikihow.com/Make-a-Turning/Threading-Lathe-Tool-Bit

 

[yooper]

A boring bar with a hand ground square HSS cutter. That's what you need to get started.

Something like this :View attachment 70504

with some of these View attachment 70507

ground to a profile like this: http://www.wikihow.com/Make-a-Turning/Threading-Lathe-Tool-Bit

Thanks now I know what to look for, all I could find was really small carbide ones. What would they be called? threading boring bars??

 

[xalky]

Those are called double ended boring bars. They serve other purposes besides threading. You can use them for boring and facing inside a bore. One end holds the tool square to the bar, the other end holds at a 45 degree angle. They're , versatile,good to have on hand, and cheap.

http://www.ebay.com/sch/i.html?_odk...t&_nkw=double+end+boring+bar+set&_sacat=11804

 

[dave2176]

Haven't tried the boring bar Marcel mentioned. I use this bar http://www.grizzly.com/products/H8300 which is left handed and turn the right handed thread backwards which I have better luck with than the http://www.grizzly.com/products/H8305 right hand holder because all internal threads I have done are blind bottomed and it is easier to start from the bottom of the hole. If your spindle can handle running in reverse without unscrewing the chuck consider this method with a boring bar or this holder. I buy the inserts from Shar's.
Dave

 

[yooper]

Haven't tried the boring bar Marcel mentioned. I use this bar http://www.grizzly.com/products/H8300 which is left handed and turn the right handed thread backwards which I have better luck with than the http://www.grizzly.com/products/H8305 right hand holder because all internal threads I have done are blind bottomed and it is easier to start from the bottom of the hole. If your spindle can handle running in reverse without unscrewing the chuck consider this method with a boring bar or this holder. I buy the inserts from Shar's.
Dave

thanks xactly and Dave, that will get me headed in the right direction. The lathe I have is a Jet 1340 gear head, so the chuck coming off in reverse is not an issue.

 

[xalky]

Haven't tried the boring bar Marcel mentioned.
Dave

It's just the old school way. The way they used to do things before they came out with all these newfangled, specialty insert requiring gadgets. I own a newfangled one also. But those old style boring bars with HSS tool bits can be used for so many things besides threading...bang for your buck. Every shop should have them, they're just versatile.

 

[benmychree]

Another option is Bokum HSS form relieve boring bars; one only needs to sharpen the top of the tool due to the form relief design (like a gear cutter) the small sizes have integral shanks, the larger ones have threaded on ends, and they also have boring tools made the same way; I have used them for about 45 years, and love them; they can be bought new, I assume, but you cann find them on E Bay as well. I dislike insert tools, as they chip easily and are expensive, and I also do not like the broached hole bars, as it is not so easy to grind a tool that is right on angle and setting. Time is money!

 

[Ray C]

One thing you need to watch-out for with the boring bars with square pinions knocked-out for HSS bits , is that the bits tend to slip. Once that happens, your thread is shot. A way around this is to grind a notch in the insert so the pinch screw will seat. The problem there is that eventually, you need to sharpen the HSS bit and the old ground notch may not allow it to stick out far enough.

How do I know all this? Well, I have a set of those sitting on my shelf -unused because they are supplanted by boring bars that take threading inserts -that don't have that problem...


Ray

 

[ricsmall]

One thing you need to watch-out for with the boring bars with square pinions knocked-out for HSS bits , is that the bits tend to slip. Once that happens, your thread is shot. A way around this is to grind a notch in the insert so the pinch screw will seat. The problem there is that eventually, you need to sharpen the HSS bit and the old ground notch may not allow it to stick out far enough.

How do I know all this? Well, I have a set of those sitting on my shelf -unused because they are supplanted by boring bars that take threading inserts -that don't have that problem...


Ray

ray,

which type threading tool are you referring to? Just trying to get specifics so I know what not to buy!!

thanks
richard