# cutting a hole in the end of a hardened cylinder



## unterhausen (Dec 17, 2009)

I want a collet chuck to hold some tubes for mitering. So I was looking through my junk collection and found a collet chuck that would be perfect, but it's hardened and there is no through hole. I faced off the surface hoping it was only case hardened, but no luck.

I'm mostly just venting, because I probably should just find another chuck. But I was using an insert designed to cut hard metal, and it would have cut through just fine if the toolholder didn't interfere with the chuck, so I'm feeling like I should be able to do what I want. I need about a 1 3/8 hole, there is only a 1/8" hole in it now.


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## gadget_lover (Dec 17, 2009)

If the insert can do it, you should be able to chuck it (the collet chuck) up (pun intended) on your lathe and drill a small hole then bore it to dimension using a similar insert on your boring bar.

Daniel


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## unterhausen (Dec 18, 2009)

The trick is getting the hole big enough that I can use the boring bar. I'm using an insert intended for hard materials. I need to get a boring bar that takes inserts like that, I have no decent boring bars yet.


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## wquiles (Dec 18, 2009)

I bought some used solid carbide drill bits that cut through hardened steel very easily. Perhaps worth looking on Ebay to see if you can find something close to the diameter you need


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## unterhausen (Dec 19, 2009)

Thanks to the people that pointed out a carbide drill would work. 
Turns out I had 3/8 and 1/2" carbide drills in my junk pile. Then I only had another 7/8" to go. I have a cabide tipped 1/2" square tool that someone had shaped like a bullet, and cut the rest of the hole with that. It was slow going because I am having some trouble with the low gears on my lathe. That meant I had to run it too fast for the interrupted cut. But it worked.


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## gadget_lover (Dec 19, 2009)

So.... Where are the pictures?



Daniel


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## unterhausen (Dec 19, 2009)

gadget_lover said:


> So.... Where are the pictures?
> Daniel


After much experimenting, there was rejoicing
You can see the hole I cut, it goes from the back of the chuck (at the top in this picture) to the spot where there is rust inside. Interrupted cut was annoying as all get out.





This is an acura-flex collet chuck that I want to use to miter tubes, so I needed a through hole. It was part of a giant (50 taper?) tapping collet chuck for a mill. The idiot that sold it to me on ebay had sandblasted the chuck, so it was a piece of junk. Fortunately, the actual collet holding part of the chuck escaped the sand storm. I really don't need super accuracy, this will be more than adequate for purpose.


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## gadget_lover (Dec 19, 2009)

Looks like a fine jobe there!

Yup, time to get sone decent boring bars.  Will and Barry can tell you how to spend the most for the best possible bar.


Daniel


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## unterhausen (Dec 20, 2009)

yeah, I decided that I had enough money to buy some boring bars, then I looked at a few prices. Now I decided I'm going back on ebay.


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## precisionworks (Dec 20, 2009)

> how to spend the most for the best possible bar.


Misprint I'm sure ... you'll want to spend the least possible to get the best possible tool 

It helps if you can choose an insert shape & size first. As an Official Member of the CNMG-4xx fan club, that shape does a nice job on bars 3/4" diameter and larger (I have .750", 1.000" and 1.750" that all take the CNMG-4xx insert). Quite a few new & used bars on eBay for that shape, and it should not cost an arm or a leg to get one or two :nana:

Smaller bars are more of a challenge, as they need a smaller IC (inscribed circle) insert to get into a smaller starter hole. There's an eBay seller-manufacturer worth looking at, Monopol Tools. Their website says they been around for 20 years, and their bars look nice and cost very little:

http://shop.ebay.com/monopoltools/m.html?_nkw=&_armrs=1&_from=&_ipg=&_trksid=p3686

Inserts are the popular (meaning: cheap) CCMT-2.0 or TCMT-2.0.

Another one is Mesa Tools, made in Oregon, low priced & very nice quality. Most bars use the TPGB insert, and Mesa also sells that insert for not much money.

http://shop.ebay.com/mesa-tool/m.html?_nkw=&_armrs=1&_from=&_ipg=&_trksid=p4340

You can play eBay roulette and buy some bars for under a dollar, but most use either proprietary inserts (expensive) or obsolete inserts. Just make sure that whatever bar or bars you purchase use readily available inserts.

You can, if you have some spare time, make your own bar from O-1 or W-1 tool steel. They aren't fast to make, as the insert pocket needs to be just right, but it's a great learning experience.


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## wquiles (Dec 20, 2009)

To complement Barry's reply, it is worth nothing that if you are going to machine aluminum that it is worth picking a bar/insert that will support Al-specific inserts, such as those made for the CNMG43x and CCGT 32.5X, which are sold by latheinserts.com:
http://www.latheinserts.com/product.sc?productId=15&categoryId=-1


Since thanks to Barry I am also a member of the the CNMG 4xx fan club, I have Al inserts from latheinserts for my CNMG 432 turning/facing tool, and 7/8" boring bar 
https://www.candlepowerforums.com/threads/246303

Will


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## precisionworks (Dec 20, 2009)

Even as versatile as the CNMG-4xx is, there are times when you have to use a smaller insert ... like this :nana:


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## precisionworks (Dec 20, 2009)

In case you were wondering, the insert is a Trigon, WCGT-008 with CVM coating. Bar is made by Everde, solid carbide, 4" long.

https://www.travers.com/htdocs/pdf/0435cat.pdf

http://www.everede.net/winserts.htm


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## unterhausen (Dec 21, 2009)

Right now I have turning/facing tools that will hold CNxx-43x and CCxx-325 
I haven't ordered any of the al specific inserts, just general purpose and hard steels. Still shopping though. Thanks for the suggestions.


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## precisionworks (Dec 21, 2009)

MSC phoned this afternoon about a nice deal on their Hertel brand 1" bar with 10 inserts ... $88.15

*• *Boring Bar by itself is 05695408 on page 912Shank size: 1” Overall Length: 12” Minimum Bore Diameter: 1.200”

*• *Inserts individually are 91789263 on page 675
IC: ½” Thickness: 3/16” Corner Radius: 1/32”

MSC Order Number: 84285451





This lady is great to work with:

Courtney Szczepanik
*800 521-9520 Ext. 5227*
*[email protected]*


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## unterhausen (Dec 22, 2009)

I get $120, maybe your contact likes you better -- which is entirely understandable

Now I'm plotting about how I can mount my collet chuck on my QCTP. Might be a little tricky.


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## precisionworks (Dec 22, 2009)

> maybe your contact likes you better


She loves me ... whenever I order 



> mount my collet chuck on my QCTP


Does it use 5C collets? Dorian, Aloris, and China make a 5C block for the QCTP. Will Quiles bought the Aloris version, I got the Dorian, both are really similar.

The 5C collet does a nice job on smaller bars, and works OK on bigger bars for lighter cuts. For heavier boring, the "regular" boring bar block for the QCTP provides a much longer bar contact area, has more mass, and allows maximum bar extension (if needed).


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## unterhausen (Dec 22, 2009)

5c isn't big enough. That's why I was cutting the hole in this chuck. I'm going to be cutting thin wall tubes, so I think that the tool post will work.


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## unterhausen (Dec 22, 2009)

It's listed for $89 in one of the sales catalogs. I am trying to decide if I should pull the trigger on that or the combo with same boring bar and the turning/facing tool
Comes with 20 inserts
*ER84285477

*


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