I had to make some round holes in some 0.090" 5052 (to mount guitar pickups) and they were 2 very odd sizes, so figured I needed an indexable boring head to do so. When I searched almost all of the hits were some obviously Chinese junk for just over $100 Cdn from Amazon. I know they actually have machine tools in China, so for the price I thought I would give at a shot. Holy crap what a mistake that was. The brazed carbide inserts are not on the tool centerline, they are about 1/8" above. To make matters worse, they are round mounts to fit in socket of head, so nothing to hold in correct plane when mounting bars in head. Only way to make them work is to grind the crap out of the brazed carbides....and since I needed to make the holes, I did so ending return-to-seller option. In the end I piloted the holes and used tapered reamers.
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Boring Head to AVOID
- Thread starter cannuck
- Start date
Chipper5783
Super User
Yeah, those brazed carbide boring bars are not ready to go out of the box (I’ve always found they needed a bit of touching up, preferably on a diamond wheel). However, the ones I have (which were cheapest available out of China) didn’t need a lot of work. The round shank was no problem (actually a good thing) then one can roll it for the approach angle and where it contacts.
I often use reducing sleeves so I can accept a number of smaller size bars in my boring heads (have 5/8” and 1” boring heads and various random boring bars from auctions, overseas, yard sales etc) so any indexing of the bar angular position is up to the operator (me).
I’m getting lots of tooling from China, mostly satisfied (one bad experience, partly my fault, but the vendor was zero support), and enough cheaper that the odd throw away is acceptable.
I often use reducing sleeves so I can accept a number of smaller size bars in my boring heads (have 5/8” and 1” boring heads and various random boring bars from auctions, overseas, yard sales etc) so any indexing of the bar angular position is up to the operator (me).
I’m getting lots of tooling from China, mostly satisfied (one bad experience, partly my fault, but the vendor was zero support), and enough cheaper that the odd throw away is acceptable.
I remember my early brazed carbide bars were wonky geometry & caused me grief. Lots of heat & smoke but not much in the way of nice cutting chips. I finally realized the misalignment in the bore yielded lots of equivalent negative rake & even varied from bar to bar. Rotating the shank & grinding them back was an option but I didn't have diamond or green wheel. I bought some 'correct geometry' I think cobalt HSS & difference was night & day. I kept the braze-ons as rudimentary boring bars for crappy steel projects in the lathe where you can compensate by height & rotation. Not all the Asian braze-ons are bad, but mine were bad.
Anyway, the world has moved on. You can get decent indexable boring bars from China for a good price, they typically use pretty common & inexpensive inserts. Just confirm the diameter that engages the BH. I seem to recall predominantly metric, but IMP are available too.
Anyway, the world has moved on. You can get decent indexable boring bars from China for a good price, they typically use pretty common & inexpensive inserts. Just confirm the diameter that engages the BH. I seem to recall predominantly metric, but IMP are available too.
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Very timely post Peter! I have a little job I am setting up to do and I was just lamenting about the lack of boring bars with carbide inserts or HSS.
Almost all of mine have brazed carbide cutters and basically they are not great. Ideally, I'd like to find new bars for them that take inserts that I already have, but I guess I would accept a different one as long as it worked on the majority of my boring heads.
ChazzC
Ultra Member
I got this 1/2” set a year ago on Amazon for US$70 (now US$80):
Accusize with the CHMW discount should have something similar or better.
Accusize with the CHMW discount should have something similar or better.
The only carbide insert boring bar set I could find on accusize was a stubby set.
4pc Indexable Stubby Length Boring Bar Set, w/ Carbide TiN Coated TCMT Inserts and Extra Screws
When you choose indexable boring bar, it works as the following tools (and solutions): indexable boring bar, short boring bar, stubby boring bar, indexable boring bar set, indexable boring bar and head, indexable boring bar 1/2, indexable boring bar 3/8, etc.
accusizetools.com
I think I have the regular length version of those. Work great.The only carbide insert boring bar set I could find on accusize was a stubby set.
4pc Indexable Stubby Length Boring Bar Set, w/ Carbide TiN Coated TCMT Inserts and Extra Screws
When you choose indexable boring bar, it works as the following tools (and solutions): indexable boring bar, short boring bar, stubby boring bar, indexable boring bar set, indexable boring bar and head, indexable boring bar 1/2, indexable boring bar 3/8, etc.
From accusize?
@David
I just missed it.
accusizetools.com
Looks like the set above is available in different counts and sizes too.
My only complaint is that I don't use that insert in anything else so I'd have to add another insert family.
I just missed it.
Round Shank, 90 Degree, Indexable Boring Bar Set
When you choose Circle Indexable Boring Bar, it works as the following tools (and solutions): Circle Indexable Boring Bar, etc.
accusizetools.com
Looks like the set above is available in different counts and sizes too.
My only complaint is that I don't use that insert in anything else so I'd have to add another insert family.
I bought them because I have a stash of TCMT inserts. From what I do not know…@David
I just missed it.
Round Shank, 90 Degree, Indexable Boring Bar Set
When you choose Circle Indexable Boring Bar, it works as the following tools (and solutions): Circle Indexable Boring Bar, etc.
Looks like the set above is available in different counts and sizes too.
My only complaint is that I don't use that insert in anything else so I'd have to add another insert family.
Ya, I can see that.
Now that I know they exist I'll have to see who else sells them and if they have Trigon or those parallelogram inserts that are used in a facing head.
Chipper5783
Super User
I have a set of those (came with another boring head, intended for the CNC) - they are fantastic. I got the specific recommended inserts (have quite a bit of positive rake) - they are very keen (sharp). I have not used the new boring head, but I have used the bars (made a sleeve for one of the imperial boring heads 1” down to 20mm). I was very happy with the results (can tickle out “angel hair”, great finish).