# Boring bars - how to pick?



## Janger (Jun 6, 2017)

@Dabbler was showing me his fancy Iscar (I think) indexable boring bar which does boring, threading and grooving by changing the inserts. pretty fancy. pretty pricey. Made me think it was time to stop fooling around with my tinny little 1/4" HSS boring bars which are just frustrating to use. Don't buy those guys from busy bee BTW. I don't really know what I need or how to pick - loads to choose from. Aliexpress has about 5000. accusize seems pretty limited - they have boring bars but threading or grooving seems to not be there. KBC has loads - pricey too.

I'd like something which is beefy and easy to use - something that will work with holes I start with my 5/8" drill bit. and it would be nice to be able to bore to 2" depth. Thread, groove, and bore. Something that used inserts that I can resharpen would be nice. anybody got any good experiences? not too expensive but decent.

some examples...

has negative rake - bad idea for my medium sized lathe which is 14x40. 2hp. Good price though.
https://www.accusizetools.com/rh-sclcr-indexable-boring-bars-with-ccmt-inserts-key-included/
inserts ccmt32.51 $53 for 10.

beefy?
https://www.accusizetools.com/rh-sclcr-indexable-boring-bars-with-ccmt-inserts-key-included/
inserts WNMG 33 $72/for 10.

cheap? old school type uses HSS lathe bits?
http://www.kbctools.ca/products/CUTTING TOOLS/BORING BARS/TOOLBIT BORING BARS/2019.aspx

same but a set
http://www.kbctools.ca/products/CUTTING TOOLS/BORING BARS/TOOLBIT BORING BARS/3326.aspx

Maybe just some of these, not too expensive, could sharpen them some, disposable. 
http://www.kbctools.ca/products/CUTTING TOOLS/BORING BARS/CARBIDE TIPPED BORING BARS/782.aspx


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## PeterT (Jun 7, 2017)

I purchased similar to #1 but through Ali for the same CCMT inserts I use for lathe tools, perfectly happy with them. If you can stand a bit longer shipping time, I'm pretty sure they are cheaper. I have found the offshore bars are sometimes different Torx screws than the 'real' ones but of no consequence. If you can buy some spare screws same time, do so. I have also lopped off the shank & turned them down for boring heads, again work very well.
https://www.aliexpress.com/item/S16...32603661551.html?spm=2114.13010608.0.0.tBvRKC

Its been a while since I looked but you may be able to find different sized shanks for same insert which is an advantage. My inserts are CCMT0602 so i try hard to standardize on them. Use the heaviest bar you can for rigidity & finish, but sometimes smaller holes necessitate smaller bar. Most Ali vendors have tables that show the min/max. I think Accu's selection is a progression so you are locked into their insert sizes where it jumps from 2 to 3. These type boring bars are not for threading though, different nose angle. I bought my inserts through ebay/Ali at much lower prices than tool suppliers. I cant tell the difference. The non-coated ones for aluminum are amazing, they cut very well.

The KBC HSS type bars are useful like for relief cutting. The perpendicular tool can only bore a through hole. Boring to an internal flat requires the style where tool broach is at 45-deg. You can grind your own profile which is useful. Or for that matter, grind a Vee & thread. These are good to have IMO. But you need a way of securing the bar in your tool holder. The typical one for our size lathe is 0.75 or 1.0" which is too big for 0.375 or 0.5" bars. I machined some split bushings.

The ones in your last KBC link is primarily for boring heads. The ones I bought for this purpose are so crappy I have used them in the lathe. But they are relatively short so limited range & you need a green wheel to dress the carbide. I just ground flats on mine & clamped them in the rectangular tool block because they won't be used in the boring head. But I see no advantage to using them in a lathe over the other options mentioned.


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## PeterT (Jun 7, 2017)

There are also some advantages to a set. I cant find the link where I bought mine long time ago, I suspect Ebay because there was some TMX brand that was getting blown out. Its like this but no fluid passages, just regular shank. And for sure was not that expensive at the time.
http://www.traverscanada.com/coolan...ring-bars-set/p/80586/?keyword=boring bar set

You might have to hunt around on Ali if you want a progressive set (but common insert). Maybe like this? 

https://www.aliexpress.com/item/5pc...lgo_pvid=f16bb7ae-7ff8-46d5-ac42-0304b77ea1fc


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## Janger (Jun 8, 2017)

Thanks Peter for the great ideas. That first Ali one is cheap! Inserts too. Although usd is awful.


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