Indexable carbide insert boring bars
#1
On another forum today there was discussion about buying a steel boring bar for indexable carbide inserts from Shars or CDCO. Those suppliers are importing tooling from China and the only thing I've been known to source from the Asian country is some tool holder blocks for my Dorian CA/40 quick change tool post.

I advised against buying insert boring bars from those sources because the steel is poor quality and the machining of the insert pockets...is worse.

My reason for posting my boring bars here is to illustrate that one can buy a few quality tools from local Craigslist or Kijiji ads, and eBay that are quality name brand tools and spend LESS money than the import junk. Here's the photo that I took today, so the latest collection (which grows by one or two per year.) This is about 6 to 7 years of collecting from those sources. No boring bar has cost me more than $82, shipped.

[Image: IMG_20150412_164822665_zpsxkuhxrk4.jpg]

From the top:

Circle Machine CCB! 250-4-5R, Ø 1/4" carbide shank, takes proprietary CDHH12061 inserts, non coolant fed, -5º lead angle, minimum bore Ø .285". I actually use this one quite a bit, despite not having any spare inserts for it.

Valenite S04H-SCLPR 1512, Ø 1/4" steel shank, uses ISO/ANSI standard CPGT 1.51.21 inserts, non coolant fed, -5º lead angle minimum bore Ø .312". I have plenty of inserts for this one, going back to using it for short extension work. Cheaper to use than Micro 100 solid carbide bars.

Kennametal E06M-STFCR 2, Ø 3/8" solid carbide shank, uses an odd but standard TPGT22x insert. Most insert in the 1/4" I.C. size would be a TCxT 21.5x, these are 1/8" thick rather than a TCxT's 2.5mm (0.097") thick. Coolant through, 0º lead angle. Gets a fair amount of use though I've yet to try pumping coolant through any of my bars. Minimum bore about Ø .450".

Valenite S08R-STFCR 2, Ø 1/2" steel shank, uses ISO/ANSi standard TCxT 21.5x inserts, of which I have plenty. Non coolant fed, 0º lead angle. I use this one for shorter, larger bores because the inserts are plentiful and easy to get cheap and I get great chip control.

Valenite VNCD 7461, Ø 5/8" solid carbide non coolant through shank, uses cheap and easy to find flat topped TPG22x size inserts. Again, I have quite a few. Uses a mechanical carbide chipbreaker, though doesn't seem to need it. I just LOVE this boring bar despite my disdain for TPG inserts. This is what those inserts were meant to do, bore holes. Minimum bore is stated to be Ø .812", though I had no problem getting into a Ø .780" bore. No fears boring a Ø 1" hole over 6" deep with this bar!

Valenite A12T-DDUNR 3, Ø 3/4" coolant fed steel bar, uses DNMG33x size inserts. Minimum bore of Ø 1.25", I've yet to use it. This one would be easy to get coolant into if I needed to, it's got 1/8-27NPT thread tapped into the end. Will be good for profiling if I ever need to do that.

Parfana S16T-MCLNR 4, Ø 1" non coolant fed steel bar takes common CNMG43x inserts. Minimum bore of Ø1.280", I tend to use this one for heavy boring when I really need to plow material off. Voted most likely to chatter if not using a high positive insert.

Valenite A24V-DCLNR 4, Ø 1-1/2" non coolant fed steel also takes common CNMG43x size inserts. This is the biggest bar that my Dorian can use with a CA-41 boring bar block. I haven't yet had a need for a bar with a minimum bore of Ø 1.780", but the minute an opportunity arises you know I'll try to kill the job with this beast.

For most lathes in the 7x12 to 12x36 range I'd suggest starting with a Ø 3/8" steel bar that takes CCMT/CCGT 21.5x size inserts. It'll be a -5º lead angle and the inserts are readily available. Yes, you only get two edges per insert but it's a much more secure pocket for the insert than other shapes and a very strong 80º cutting edge. A bar that uses TCMT21.5x inserts is also good, though the 60º included angle of the cutting edge requires more caution.

Thanks for playing along.

Ken
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#2
Nice collection Ken.

A good place to get new boring bars that are of reasonable quality is Maritool. I've bought a fair amount of tooling from Frank and haven't had an issue with any of it. I need to start watching eBay since you get such good deals. My choices are more limited though since my QCTP takes 5/8" tooling as the maximum.

Ed
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#3
(04-13-2015, 03:47 PM)EdK Wrote: Nice collection Ken.

A good place to get new boring bars that are of reasonable quality is Maritool. I've bought a fair amount of tooling from Frank and haven't had an issue with any of it.

Ed

You had my hopes up there for a few minutes Ed. I started looking at a 90° shell mill there, but apparently they don't have a lick of R-8 tooling?   17428
Willie
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#4
(04-13-2015, 04:46 PM)Highpower Wrote:
(04-13-2015, 03:47 PM)EdK Wrote: Nice collection Ken.

A good place to get new boring bars that are of reasonable quality is Maritool. I've bought a fair amount of tooling from Frank and haven't had an issue with any of it.

Ed

You had my hopes up there for a few minutes Ed. I started looking at a 90° shell mill there, but apparently they don't have a lick of R-8 tooling?   17428

Yea, he quit selling R-8 tooling. I'm not sure why. 17428

Probably too much competition so not worth it for his business model.

Ed
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#5
You can find decent face mills on eBay and they're often a "shell mill mount" style rather than direct R8 mount. That's the way mine are so I simply get a matching pilot diameter R8 to 3/4", 1" or 1-1/4" holder. It adds a little bit of length, but when a better cutter comes up on eBay (like my Walter cutters), you just swap out the cutters and reuse the holders.

I do know you can get direct R8 shoulder and face mills from the likes of Shars, but I wouldn't use one of their POS cutters as a fishing sinker let alone as a cutter for metal. Junky cutters with even crappier inserts. Not worth the effort nor the money IMO.

In fact, they have boring bars too, and that hard earned reputation is why you see a small array of quality makers in my list. I'd buy Walter-Valenite, Seco, Sandvik Coromant, Kennametal, Ultradex, Mitsbishi, Kyocera and a few other well known makes before I spent good money on questionable tools. I've leaned how to become a certified Master of eBay Deals!

Willie, what size cutter would you like and how much HP does your mill have? I would be happy to help you find a bargain on something good.
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#6
(04-13-2015, 07:18 PM)PixMan Wrote: I've leaned how to become a certified Master of eBay Deals!

Willie, what size cutter would you like and how much HP does your mill have? I would be happy to help you find a bargain on something good.

That you have Ken... that you have!  
Every time I find what looks like a good deal on inserts, it's for a type/size of tool that I don't have.  Bash

I think I would like to have a 2" cutter. The mill is only 1-1/2HP but I don't do any heavy cutting anyway. I just want to give a face mill a try for a change. My mill knocks too much if I start pushing a fly cutter past a certain point. I'm hoping a multi-insert cutter would help there.

I started out with all the cheap import cutting tools in the beginning like a lot of folks do. I came to the conclusion that HSS tool blanks made in India must be made from recycled 'Land-O-Lakes' margarine sticks. Then I got my hands on a few good tools and that really opened my eyes. But I still have to live within my ever shrinking budget. So I would rather pass on the Shars, Travers, etc., type stuff these days and save a little longer for something decent. And I don't have to have a direct mount, an arbor is fine with me and preferable actually because of the reason you sited above. But.... I want something with commonly available inserts and not have to jump through all kinds of hoops to track some of them down.

It's a case of want - rather than need, as usual.
Willie
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