.0001" boring heads. Opinions of Kennametal tenthset?

A question in regards to boring heads that can be adjusted in .0001" increments. All the ones I have can only be adjusted by .001". I need to bore some holes and need to be as close to the dimension as possible.

Are these .0001" boring heads that good when you adjust them or no better than a .001" head?

I have found a Kennametal tenthset #50 boring head in very good used condition. Are they worth the money?

They should be great as long as you do your job compensating for any tool pressure. This is more important with a long flexy bar than a short stiff one.

Laverda said:

A question in regards to boring heads that can be adjusted in .0001" increments. All the ones I have can only be adjusted by .001". I need to bore some holes and need to be as close to the dimension as possible.

Are these .0001" boring heads that good when you adjust them or no better than a .001" head?

I have found a Kennametal tenthset #50 boring head in very good used condition. Are they worth the money?

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What eKretz just said. It's about 50% up to your bar, structure, & bearings, 50% up to the head. The King of that bar has to supply the other 200% to hit and hold tolerances like that.

Two sizes of Chandler-Duplex for me. Long-gone maker, but the Kennametal has certain similarities. Either family of heads are better than my mills ... or me!



Not hard if you do it every day. The skill and familiarity with what to expect of the same-old, same-old machine kinda "grows on yah" like any other op done often.
Tedious as all Hell to even hold a thou if done near-as-dammit never.

No way around it. Your head more than the hardware boring head.

Can't get that of no two-page poop-sheet. Have to try it in the metal on your own machine and materials, then adapt. Repeat 'til it comes good.

THEN you "own it".

Even CNC ain't magical. It is just more patient and remembers better without gettin' tired or pissed-off than Old Farts on wore-out bars doing a task but a few holes a calendar quarter. Or year.

Termite another worthless dumb assed post from you! If you ever even tried to any machine work you would have a clue.
I would suggest reading the instruction manual for the Romicron boring system. There the parameters are given for boring holes to sub tenths, a lot of it is related to the machines capabilities.
The Erickson and Romicron heads have very little offset for balance, not really as useful as a standard Criterion head for general work on regular mills.

I've used the Bohrstar kits from Techniks with GREAT success holding tenths for bearing bores. Pricey, but the kit will get you from .315 to 3.94 with the different bars (all inserted) and components. They use a special holder with a pin and tapered screws to pull the boring head onto the shank tight.

Mike1974 said:

I've used the Bohrstar kits from Techniks with GREAT success holding tenths for bearing bores. Pricey, but the kit will get you from .315 to 3.94 with the different bars (all inserted) and components. They use a special holder with a pin and tapered screws to pull the boring head onto the shank tight.

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Given "Bohr" and "Pinz" suggest Austria or Germany as to "made in Europe", yazz, that should be good news, indeed.

Iscar ITS-Bore. If they still make it. Mine is old (20 years?) and has multiple bars and heads for a wide range.
have fun
i_r_

i_r_machinist said:

Iscar ITS-Bore. If they still make it. Mine is old (20 years?) and has multiple bars and heads for a wide range.
have fun
i_r_

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By "still make it"... ISTR my no-longer-young as-off the 1960's metallurgist mentor telling the "sad but true" joke about Packard and Ford.

Where do bores live in great number? IC engines.

Seems Ford had unpgraded a production cell that processed V-8 engine block and bragged they used the same equipment as still-legendary Packard used.

Packard guy just laughed.

Said it was true as far is it goes as to maker of the equipment.

But that what Ford did NOT tell you was that Packard was capable of routinely measuring to a hundred thousandth of an inch, holding a tenth all run, whilst Ford ran the same equipment at twice the throughput and one-tenth the tool change interval to not really even hold one thou reliably!

Guess who had engines that sucked oil and smoked earliest?

Packard-Merlin aero engine had a longer Time Before Major Overhaul than a Rolls-Royce built Merlin had, too!

i_r_machinist said:

Iscar ITS-Bore. If they still make it. Mine is old (20 years?) and has multiple bars and heads for a wide range.
have fun
i_r_

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We have one at work, bought it about six years ago, excellent tool, easy to hold size, was just a little expensive!
BTW, these are made by D'Andrea......here's a link!

Modulhard’Andrea | D’Andrea S.p.A

Kevin

I have Tenthset heads in 3/8 and 1/2" sizes. I am quite satisfied with them. They are my favorite boring heads. Beware of any Tenthset that was used with coolant. Both my Tenthsets were bound up when I got them. They needed to be disassembled and washed with hot water to get rid of the caked coolant.I am 83 and long retired. I have a thing about boring heads. I think I own 8 or 9. 2 Tenthset, 2 Enco/Gamet boring and facing,2 d'Andrea boring and facing,a Bokum and a DeVleig, and maybe 1 or 2 I have forgotten.

You didn't say what size and depth of bore you want to do with the tenthset. A #50 is a 1/2" shank. I would trust it to hold size when finish boring to perhaps a 3/4 hole, limited by the configuration of your boring bar. Above that I would use something else. Its small size doesn't give the off balance of a traditional offset boring head, so it allows for faster spindle speeds. Years ago we had no problem holding size even when cycled through a tool changer. I have never used one with a 90 degree tool configuration.

I used a Criterion 202 for years on my little Clausing mill and could never bore bearing pockets etc. or anything else "close".

That all changed when I finally found a used Wolhaupter in decent condition.

Also good inserts and/or properly sharpened HSS tooling makes all the difference. A buddy put me on to these:

https://www.iscar.com/eCatalog/Family.aspx?fnum=1682&mapp=IS&app=28&GFSTYP=M

I have a Kennametal tenths boring head mounted to a #30 Erickson QC holder. I was boring 1.5" deep by 3.314" diameter in mild steel using brazed carbide with a 1/2" shank, taking 0.020" DOC. All that being said I had a hard time holding + or - 0.0005". My Tree mill is old so has some wear but even with new spindle bearings and locking X&Y I couldn't hit tenths on a good day. As said by others, the machine and the operator are a significant factors in hitting your numbers.

Have a 3 different size Iscar ITS-Bore kits and really like them. They are 10 years old and have some back lash, however I know them and their limits well, they are nice to use and can hold tenths when done correctly. Or should I say familiar with them.

I have two of those tenthset heads. Great stuff. Don't use 'em for gross stock removal, not built for that. I've used Criterions and others but to crack the bar a tenth, you have to set up a 0.0001 indicator with a flat faced "point", same as I did with DeVlieg- style bore bars.

The R8 spindle has very bad repeat capability, but a machine with great tool change repeatability like the odd Moore jigbore spindle, the tenthset type heads can be set up and used for the finish cut on repeat jobs.
The early style Erickson heads, used a collar for adjustment, the later used the more conventional dial, like the Moore boring head.

machinistrrt said:

... but to crack the bar a tenth, you have to set up a 0.0001 indicator with a flat faced "point", same as I did with DeVlieg- style bore bars.

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Yahbut.... look when DeVlieg brought that system into the market. Still ancient HSS days, not high-repeatabilty Carbide "inserts".

So THEY had a whole support "infrastructure" for doing that "cartridge" pre-setting, Off machine. Absent that, a body has to substitute. On the spindle. As you have been.

PITA? Not in low-volume or infrequent use, not really.

Nobody else has an AFFORDABLE rig for self-calibrating that measures and compensates for cutter variations automagically, either.

Separate spend and higher-end, not entry level, CNC system to USE it with, those are.

Manual machine?

YOU must become that "system!"

Meaning there are more sub-optimal answers than highly optimal ones, and even the "right" choice will depend on WHOM is running a given head in WHAT, for WHICH, and off WHATEVER spindle at what budget in TIME vs investment cost and learning curve.

It's PM. Such "variables" and value-for-money safe enough bets are what we explore best.

OP came to the right place. But he, not we, still has to do the "deciding" part.

i_r_machinist said:

Iscar ITS-Bore. If they still make it. Mine is old (20 years?) and has multiple bars and heads for a wide range.
have fun
i_r_

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ITS-Bore is made by, or under license from, D'Andrea. The fine boring heads are identical to and interchangeable with D'Andrea Testarossa series heads and the Modulhard'Andrea tooling system.

The system is a pretty massive upgrade from older precision boring systems like Tenthset, and also has an advantage over other modern systems like Big Kaiser, Seco EPB, Sandvik Corobore etc. in that the Testarossa head is adaptable to both centric bars for small holes, and peripheral cartridges for bigger holes. The other systems are all separate heads for centric/peripheral, which is a pretty huge cost delta.

Those mentioned above are all 2µm resolution heads with exceptional accuracy and repeatability, and make boring under 10µm trivial even for unskilled operators. They are expensive.

The Pinzbohr system is a pretty good compromise - not quite in the same league, but priced more reasonably than any of the above.

At the other end of the spectrum, if you're used to old school boring heads like Criterion etc., then the Tenthset is a very nice upgrade in precision.

thermite said:

Yahbut.... look when DeVlieg brought that system into the market. Still ancient HSS days, not high-repeatabilty Carbide "inserts".

So THEY had a whole support "infrastructure" for doing that "cartridge" pre-setting, Off machine. Absent that, a body has to substitute. On the spindle. As you have been.

PITA? Not in low-volume or infrequent use, not really.

Nobody else has an AFFORDABLE rig for self-calibrating that measures and compensates for cutter variations automagically, either.

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Agreed. We used cemented carbide on those DeVlieg cartridges, and when used on the DeVlieg machine, were wonderful, would repeat over the run to a tenth or two. On the other hand, when adjustment was necessary, you did the whole dance.
I had always considered the Tenthset head as a toolroom item, that's how I used it, it's just not stout enough for Otto the hammerman.

machinistrrt said:

Agreed. We used cemented carbide on those DeVlieg cartridges, and when used on the DeVlieg machine, were wonderful, would repeat over the run to a tenth or two. On the other hand, when adjustment was necessary, you did the whole dance.
I had always considered the Tenthset head as a toolroom item, that's how I used it, it's just not stout enough for Otto the hammerman.

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Well surely. Look at the guys lucky enough to score a "Tree" boring, surfacing, AND taper head!

One eyeball at the arm... and you get an "oh SHIT! moment"

Not "am I patient enough to tread carefully".

Surely we can be.

But "can I even put tool to the bugger that is actually any GOOD at shaving as lightly as that fragile arm has to cut to not deflect into takes all-day, ruint work, an end-of-life crash, or some combination, thereof!"

I don't even care to "go there" on my "all manual" Old Iron.

Not when NOWADAYS there's a hundred guys that have CNC and can just give it a wish list on code and it generates the cone, cylindricals, and flat faces as if it didn't give damn WHAT sort of preversion you had asked it to create , so long as in the right sequence to allow it, not try to finish-bore a hole as doesn't yet exist!



Bores held to a tenth on Old Iron? Why do I own a "Precise" spindle mounted die ginder? Why do I know about a process - I can send out for, even - called "honing?"

Sadly obsolete Old Fart, I guess?
Guilty on all counts.

BFD. I still eat well enough if I hand-off stuff to better men .. or at least more appropriately equipped!

Try to snatch EVERY crumb off a specialist's plate?

Who TF is it now doing the job YOU were the success at . .back when you still had the time to do it well?

Need to do tenths? Make the OVERALL investment that assures it.

A good "mothership".

Not just good tooling astride a horse as can't walk a straight line to begin with.

Mind. OP never said.

Funny as Hell he comes back with mega-HP worth of Mazak or the like, and a Cat 50 nostril, when some puffed-up hobbyist is chattering about "Are ATE"!

40 taper here since you asked. Not that it can let me walk on water... That's another one of those jobs for a more expert hand.