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Where to find? Solid carbide thread relief/ back chamfer boring bar..................

david n

Diamond
Joined
Apr 13, 2007
Location
Pillager, MN
So I can't find these little bars any where any more.(see pic)...................This one is a circle machine(who is now Widia?) and I believe they no longer make them.....................I found a different brand one time...maybe Harvey?................but the 1/8' wide cutting edge has a side clearance angle and does not cut a flat bottom groove.................any one know where I can fid some just like my pic?


IMG_0709.jpg
 
I use these for my recess tools on Brown and Sharpe Screw Machines. They are very hard to find and can take a while to get if its backordered.

I order solid carbide boring bars and grind them myself. It only takes 10-15 min to get it right.

Pretty cheap overall to do it yourself.
 
I use these for my recess tools on Brown and Sharpe Screw Machines. They are very hard to find and can take a while to get if its backordered.

I order solid carbide boring bars and grind them myself. It only takes 10-15 min to get it right.

Pretty cheap overall to do it yourself.


I have some small diameter solid carbide boring bars that Micro100 and Harvey didn't want to make due to a custom length (1" overall) that these guys made to a drawing for me, for the same price as an off the shelf micro100. QUICK TURN SPECIALS | MITGI
 

These will do................thanks.

They are for a higher(ish) volume 1 OP part in 6061 that has little margin...............I bore and back chamfer with this tool with no need to deburr the through hole by hand after part off. They go right from the machine into the shipping box. I've tried tools similar to Frank's and other grooving tools, but the one I'm after is nice and sturdy and lasts a very long time. Others like to snap off if the material is gummy.
 
These will do................thanks.

They are for a higher(ish) volume 1 OP part in 6061 that has little margin...............I bore and back chamfer with this tool with no need to deburr the through hole by hand after part off. They go right from the machine into the shipping box. I've tried tools similar to Frank's and other grooving tools, but the one I'm after is nice and sturdy and lasts a very long time. Others like to snap off if the material is gummy.

Makes sense. I used to make the same tools when running parts on a hydromat. Full form is the way to go.
 
I knew I saw those somewhere but I couldn't remember for the life of me that you sold them.


/hijack
Frank I noticed that you removed from your website the Cat40 dual contact longer 1/8" tapered end mill holder. Do you plan on having more in stock soon? They literally got removed 10 minutes after I forwarded the purchase order to the boss lol. What timing!

Thanks.
/hijack off
 
I knew I saw those somewhere but I couldn't remember for the life of me that you sold them.


/hijack
Frank I noticed that you removed from your website the Cat40 dual contact longer 1/8" tapered end mill holder. Do you plan on having more in stock soon? They literally got removed 10 minutes after I forwarded the purchase order to the boss lol. What timing!

Thanks.
/hijack off

Yea hard to imagine how popular 1/8 shrink fit holders are. We are doing our best to replenish or stock. Some longer gage lengths and some Metric sizes are in the works.
 
These will do................thanks.

They are for a higher(ish) volume 1 OP part in 6061 that has little margin...............I bore and back chamfer with this tool with no need to deburr the through hole by hand after part off. They go right from the machine into the shipping box. I've tried tools similar to Frank's and other grooving tools, but the one I'm after is nice and sturdy and lasts a very long time. Others like to snap off if the material is gummy.


OK, I don't git it?

For thread relief, I git wanting this tool....

But you now say that you want it for back chmf.
But you didn't like the one that you posted at the top doo to back taper.

That back taper is there for exactly the porpoise that you are looking for.
To keep the cut-off thin next the part, and thicker on the bar.

... but I take that one step further, and I use a threading bar if applicable, or even just recess with the boring bar a bit.


Please 'splain why you are Adam Ant aboot having the straight surface?
Is it just so that you can use it for actually relieving threads at some later date, and don't want to deal with 2 different tools?


----------------------

I don't drink and I don't smoke
Ox
 
With a wet surface grinder and simple fixtures, such tools (boring bars) are easy to make out of drill shanks or bought carbide blanks. One can make them with faceted features using a simple V block, For determining clearance angles one can draw a segment of a circle at a higher scale, and then draw the cutting portion using a simple protractor. Primary clearance being perhaps 7 to 10* inside what ever part ID and then secondarys as the drawing shows that you need to clear the part.

Rolling the circle grind can be also done out of a V block but better to use a homemade V block so not to wear out your precision one. A V block made of nylon is good for this because it acts as a bearing for easy turning and can be trued up on a mill or grinder.

Yes a spin index, even a bargain brand can be used like a work head, best to drill a bolt hole in the spring index base and then bolt it to the side of an angle plat for tilt angle, using a simple hand protractor.

One can cut a milk bottle plastic washer to slip over the spin index barrel nose to become a shield to keep abrasive out of the spin index works. Still doing this kind of work you are likely to wear one out in a year or so.

One can make a brass nose spring finger to click into the index holes of a spin index for faster use. For very fast use one can grind notched in the OD of that diameter to make a 12 index because it is much faster to have a smaller index number.

*One biggest problem with boring bars is to be sure the area under/below the cutting edge will not hit or rub on the part except the actual cutting edge. Very special care to watch for this problem or one will have nothing but problems. The old school method was to hand-hold a boring bar to a hole of the same size and eyeball it to see that no parts of the heal would bump it inside of the part.
 
I make tools like this out of old broken #5 x 5" [KEO] center drills on my spindex.
I prefer to buy, but when that option isn't timely or I have time to burn, then I make my own.
It's good to know how to make Schidt for emergencies.

However, I still have the same MSC import 5C spindex that I bought in '89.
I don't understand what you are dooing to your unit(s) that is killing them?


---------------

Think Snow Eh!
Ox
 
QT: don't understand what you are dooing to your unit(s) that is killing them?

I was talking about using one for a grinding work head. Likely it would not last for a very long time.
As long as a grinding machine work head.
 
OK, I don't git it?

For thread relief, I git wanting this tool....

But you now say that you want it for back chmf.
But you didn't like the one that you posted at the top doo to back taper.

That back taper is there for exactly the porpoise that you are looking for.
To keep the cut-off thin next the part, and thicker on the bar.

... but I take that one step further, and I use a threading bar if applicable, or even just recess with the boring bar a bit.


Please 'splain why you are Adam Ant aboot having the straight surface?
Is it just so that you can use it for actually relieving threads at some later date, and don't want to deal with 2 different tools?


----------------------

I don't drink and I don't smoke
Ox

I'll 'splain...................The one in the pick makes a flat bottom groove with a 45° back chamfer............that's what I'm goin for.............other similar bars have a few degree angle on the groove cutting edge. Here's one....................https://sct-usa.com/wp-content/uploads/2019/05/2019_sp_backcham.pdf.....................see the 2° back angle on the cuttin' edge? If'n I used that tool to back chamfer and then come in with my parting tool, she'd have a nice fat burr when it drops.............​the tool in my first pick is years old.................they last a long time. I need a few new ones cuz I can only go .750" deep with the ones on my shelf. The new part I'm runnin requires at least a 1" long bore depth................sure I can grind one up, but it looks like this one off the shelf will do just fine.........................http://internaltool.com/products/details/thread-relief-tools/?id=46-1145
 
I'll 'splain...................The one in the pick makes a flat bottom groove with a 45° back chamfer............that's what I'm goin for.............other similar bars have a few degree angle on the groove cutting edge. Here's one....................https://sct-usa.com/wp-content/uploads/2019/05/2019_sp_backcham.pdf.....................see the 2° back angle on the cuttin' edge? If'n I used that tool to back chamfer and then come in with my parting tool, she'd have a nice fat burr when it drops.............​the tool in my first pick is years old.................they last a long time. I need a few new ones cuz I can only go .750" deep with the ones on my shelf. The new part I'm runnin requires at least a 1" long bore depth................sure I can grind one up, but it looks like this one off the shelf will do just fine.........................http://internaltool.com/products/details/thread-relief-tools/?id=46-1145


.. and this is where we are not on the same page....

The few degrees back taper makes it more likely to NOT have the flag burr at drop-off.

Ass-u-ming that we are talking the same thing here.... ?
You are lining up the inside edge of your cut-off to the corner of the 45 and the flat - right?

Are you seeing what I'm saying?
The back-taper gives you a thicker wall between the air and your cut-off tool - on the bar side than it does to the part side - than the sqr tool does.
???

This is why I have gone the route of just using a threading tool or whatnot for the same porpoise.
I don't see the need to take all that material behind the part out through the part hole, when the cut-off can take it out later.
I doo run my 60* tool down in on a 45* motion - so's to have the 45* chamfer on the back of the part, but whatever is after that is 100% pointless IM/HO.


???


-------------------

Think Snow Eh!
Ox
 








 
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