04-12-2015, 09:30 PM
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]](http://img.photobucket.com/albums/v466/kenm10759/Dads%20shop/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
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.
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