I need a internal threading tool recommendation

The bug issue with the solid carbide boring bars is they have ZERO forgiveness. All you will hear is a "tink", and you will now have a 2 piece bar.
I have an import bar with IR08 inserts I believe, that will fit in a hole about .375".
Joe Hynes
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martik777 said:
These work well and cheaper on ebay but you can read reviews here: https://www.banggood.com/Internal-L...-p-1032420.html?rmmds=search&cur_warehouse=CN

I have a full set of similar insert tools from them and they all work great, especially the parting tool.

You will want to get a thicker boring/threading tool for heavier cuts
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I have the 12mm version of this threading tool and have yet to use it.

The problem is the size of the insert limits the threads to 1.68mm ( 15TPI) or finer. My 12mm bar requires a minimum bore of 13.4mm (.526") or larger. The standard threads that I can cut are 5/8-18 and 3/4-16 and NEF threads 5/8" and larger in inch sizes and 16mmx1.5 and 18mmx1.5 in metric.

The 10 mm bar will add the 1/2-20 and 9/16-18 and the 11mmx1.5 to the range.

I also bought the tool set and aside from the internal threading bar, use them most of the time.
 
RJSakowski said:
I have the 12mm version of this threading tool and have yet to use it.

The problem is the size of the insert limits the threads to 1.68mm ( 15TPI) or finer. My 12mm bar requires a minimum bore of 13.4mm (.526") or larger. The standard threads that I can cut are 5/8-18 and 3/4-16 and NEF threads 5/8" and larger in inch sizes and 16mmx1.5 and 18mmx1.5 in metric.

The 10 mm bar will add the 1/2-20 and 9/16-18 and the 11mmx1.5 to the range.

I also bought the tool set and aside from the internal threading bar, use them most of the time.
Click to expand...

Is Banggood the CN version of Amazon? It looks identical but since it says ships from CN and mentions US Dollars for the product. I am guessing thats what it is which probably means I could look up anything linked to Banggood on Amazon since it is more local and it would probably be on there as well? I did see these, I just did not know how small of a bore I could get them in so thanks for the help there. It seems most of the threading tools I look at say it can cut "X" and finer. So you mention cutting 1/2 -20 and I would need to cut 1/2 - 28. I assume this bar would do that since it is finer than 20 TPI? Am I understanding that correctly?
 
I don't believe that they are. The range of items for sale is far more limited. Amazon resells or brokers sales from a large number of vendors while BangGood appears to deal only with internal sales.

If you are cutting a 1/2-28 thread, there shouldn't be a problem. The thread profile is smaller for 28 TPI which works for that insert and 75% thread would require a 15/32" drill or .469" clearance hole. While I haven't measured the distance from the point of the insert to the back of the SNR0010K11 bar, my SNR0012K11 measures .526" which would be the minimum clearance hole required. The SNR0010K11 is 2mm (.079") smaler in diameter so the minimim clearance hole required should be .447".
 
Liljoebrshooter said:
The bug issue with the solid carbide boring bars is they have ZERO forgiveness. All you will hear is a "tink", and you will now have a 2 piece bar.
Click to expand...

Hey Joe, I've heard that "tink"! I gave up a very expensive Kennametal boring bar and it was all due to my own stupidity. I used it in a tool holder that used set screws to lock the bar in the holder. Snapped it right in half. I've had pro machinists tell me that they never snapped a carbide bar like that and that I was wrong - maybe, but when I spoke to a Kennametal rep on the phone he laughed and said it happens far more often than you might think. Always best to use a circumferential holder like an Aloris 4D with these bars.
 
Liljoebrshooter said:
The bug issue with the solid carbide boring bars is they have ZERO forgiveness. All you will hear is a "tink", and you will now have a 2 piece bar.
Click to expand...
mikey said:
Hey Joe, I've heard that "tink"! I gave up a very expensive Kennametal boring bar and it was all due to my own stupidity. I used it in a tool holder that used set screws to lock the bar in the holder. Snapped it right in half. I've had pro machinists tell me that they never snapped a carbide bar like that and that I was wrong - maybe, but when I spoke to a Kennametal rep on the phone he laughed and said it happens far more often than you might think. Always best to use a circumferential holder like an Aloris 4D with these bars.
Click to expand...

Man o man, I must be very lucky! :big grin:

I have yet to hear that "tick". Well I have heard the tick from breaking carbide inserts & end mills but never on any of my solid carbide boring bars, not even a chip.

Maybe my luck is purely coincidental? On my import holders, like many, I change out the set screws before even using them but for two reasons. Second reason, the tools are hard, I don't like (or see a need) cut point set screws trying to dig into my tool shanks so I use flat tip set screws for all my tools. My Dorian holders came with cup point set screws but they don't have sharp cups, they're smoothened over. Still I machined them flat anyway.

Also when I tighten down my tools, I use a t-handle hex & just snug them, no gorilla tightening (not needed IMO), and the hex shank on my t-handles will twist under load anyway. I also start with the two inner set screws first, then snug up the outer two, then follow up again on all four.

Maybe this is a why I have never broken any carbide boring bars? Never even broken any of my small Micro100 carbide bars either. The faint set screw marks on my boring bars prove that I adjust them often. Been using them like this from day one & never had a problem. :dunno:


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I consider that broken bar to be fortuitous because it made me take a good, long look at boring bar holders. There is no question in my mind that a circumferential holder is more solid and stable, especially when the bar is at maximum extension. I used my shop-made circumferential holder to hold onto a 3/8" diameter steel AR Warner bar to go 4" deep in aluminum. You are not supposed to be able to go that deep with a steel bar, at least not accurately. That thing bored an air bearing fit that required me to drill a hole in the top of the work piece to let out the air so I could get it to fit down on the rod it was meant for. I'm convinced that it isn't the bar as much as it is the holder.

I use carbide bars more than 95% of the time and they cost real money but truth be told, I am less worried about breaking them than I am about performance. I've used various holders and after testing the ones I own, I am absolutely convinced that a circumferential holder reduces the potential for chatter and improves consistency in the cut. Hence, my bias. However, I don't expect anyone to follow my lead on this. I just wanted to tell you why I feel the way I do.
 
I get it & I agree that a "circumferential" boring bar holder will be more rigid. On another forum before I came here a number of guys swore by using QCTP 5C collet holders to hold their boring bars.

Call me lazy I guess, I just never had an interest to make any yet. I continue to use the v-groove & HD boring bar holders cause they're "indexable". Technically my HD boring holders are some what circumferential but the newer generation Dorians that I'm using still uses set screws to mount the bar. I adjust boring bar lengths quite often. I can just loosen the set screws, adjust length, & be on my way without having to readjust for rake & cutter height. Now of course I'm relying on how accurate the holders are & a fixed rake.

For what I do I have gotten by just fine. If/when I need more rigidity or the adjustability for a project I may make one. Until then I'll continue to be lazy & enjoy the time saving. :big grin:
 
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