Looking for a internal o-ring groove tool

[mmcmdl]

Ground up HSS blanks , make one like the small one and mount in an easily made holder . More than one way to skin a cat .

 

[Video_man]

I realize you're asking about inserts, but sometimes HSS is the easiest and best answer. Attached is a simple tool that took about 5 minutes to grind on an ordinary bench grinder, and inserted in a common boring bar. I used it extensively to cut internal retaining ring grooves in cast iron bores, only needed an occasional touchup. (looks like one has to click on the image to open it up, the working part gets cut off on the thumbnail)

 

[mmcmdl]

He needs to be flush with the bottom of the bore . But yeah , just alter the bar so that the tool is flush with the end of the bar . Cheap and easy !

 

[Video_man]

He needs to be flush with the bottom of the bore . But yeah , just alter the bar so that the tool is flush with the end of the bar . Cheap and easy !

Thanks, missed the flush part. However, these inexpensive boring bars also have a 45 degree hole, would be no trick at all to grind the toolbit to compensate for the angle, it can stick out past the end of the bar with no trouble.

 

[mmcmdl]

Absolutely . I have a few hundred home made bars . Easy to just mill a slot in the end , square the top and use two set screws thru . This is nothing new and a $250 tool is not needed . I hope he realizes this .

 

[Winegrower]

Here is a holder that will do most all of the things you are looking for I think.
The holders are either left or right, and the inserts are also. The holders are Kennametal NER-123B on the right, and NEL-123B on the left. There are numerous radiused and straight inserts…one number on a radius grooving insert is NR3062L and KC850. It somehow tells the radius, but I don’t understand how to read it yet.

Edit: NR3062L is a “Top Notch” “Full radius” “Size 3” “0.062 Radius (0.128” diameter)” “Left hand”.

I got these from a Craigslist ad, bought a bunch of great items in a big lot, but as nearly as I can tell I paid about $8 per holder and $3 per insert.

To cut an inside groove you could use the NEL and turn in reverse, or use the NER in forward.

 

[mmcmdl]

I got these from a Craigslist ad, bought a bunch of great items in a big lot, but as nearly as I can tell I paid about $8 per holder and $3 per insert.

You suck in a good way !

 

[GunsOfNavarone]

My biggest concern is stainless, secondly Titanium. HSS is out, but I'm not sure if there are carbide blanks to make an insert. What winegrower has looks good. Although I thought the HSS tool I made would work easily, it's .500" vertical size actually rubbed on a 2" ID at the bottom of blank, against the radius of part. I ended up grinding that away, but winegrowers tools would definitely have the same issue. If I were to do a .750" ID, I think those Micro 100 tools would be the only realistic answer.
This brings up a question, I assumed turning tools (normal OD Z turning would be fine for ID turning as well. It surprised me how much shorter vertically the tools need to be to clear the inside radius. I appears that unless you are turning something larger than 3" diameter, you're gonna rub in a lot of situation (?)

 

[Winegrower]

The Kennametal Top Notch line is pretty complete for facing, grooving, etc. There are a bunch of different classes of insert material for machining various metals, and several pages in their catalog to help select the right insert.

I saw the holders above for $45, so it’s not an absurd price like some similar products. I tried them out yesterday and I’m quite pleased…these are going to address some somewhat unusual applications like trepanning, where the catalog shows minimum radius cuts and depths, etc.

I have no financial interest in Kennametal.

 

[Winegrower]

it's .500" vertical size actually rubbed on a 2" ID at the bottom of blank, against the radius of part. I ended up grinding that away, but winegrowers tools would definitely have the same issue.

You can’t see it in the pictures, but the holder is made already ground away. The catalog shows internal grooving to as low as 0.44” diameter bores.