I recently purchased (received 11 Dec 06) a R8 boring bar and head set
(model 800-5945) from H&H Industrial Products:
The head works quite well. However, the boring bars are no so
fortunate. The brazing of carbide inserts to bar is quite sloppy, with
little bits of braze metal in the wrong places, such as on the face and
edges of the carbide insert, and the nearby surfaces of the steel bar,
and the braze-metal surfaces looking pebbled or bubbled, as if
overheated during brazing.
But the brazes do look strong enough, so perhaps this is cosmetic only,
and I attempted to bore a ~1.00" diameter hole in a piece of 0.250"
thick 5025 aluminum plate, starting with a 7/8" rough hole, taking
~0.020" diameter passes, using the smallest boring bar provided, 3/8"
shank by 2.25" overall length.
Total failure. The tip of the boring bar is not correctly shaped,
allowing the heel of the carbide insert to drag on the walls of the
hole, preventing the cutting edge from touching the wall, so the bar was
totally unable to cut, and was instead trying to force its way through
the metal. Much drama, but fortunately I was able to stop it in time,
and nothing was damaged. The advantages of a manual machine.
I substituted a used Criterion boring bar (SBT-375A) of similar size
(OAL is ~3.20", tip is slightly smaller), and everything went well, so
the head is not the issue. In fact, the head appears to work perfectly.
Now, in the catalog description of 800-5945, it claims a minimum boring
diameter of 0.197", which is one fifth of the 1.00" that didn't work, so
the smallest boring bar should have worked, but cannot. Actually, the
tip of the boring bar is about 0.36" in diameter, and so 0.197" would
be impossible even if the heel didn't drag.
So, there are two problems. The product is not quite as described, and
the provided boring bars are not suited for their intended function.
My guess is that the final grind-to-shape step was omitted during
manufacture of the boring bars.
H&H Customer Service replied on Monday 18 Dec 06 to my query of the
prior evening with an email saying that their guy that knows about this
product will investigate. Stay tuned.
The "import" boring heads are fine - I use one for a number of year w/o
The brazed-on carbide boring bars are of much lesser quality. I
buying indexable bars, decent ones can be had fairly cheap (McMaster
You can play with rake and releif angles of boring bar by turning it
the boring head's mounting hole. Takes a few tries to get the proper
In general, up to 3/4 ID should be reamed, if possible. Some holes, in
stock :), can be bored on a lathe, mounted on a face plate or 4 jaw
Boring on a lathe might be more accurate as the tool won't flex
due to centrifugal forces. Or course, there's always flex due to
but that one is directed _inward.
If you want to bore smaller ID holes, consider buying indexable _solid
bars . Those can get very expensive (MSC/Enco sells Tigons for
$90 in a set), but they flex the least.
When boring on a lathe, you can angle the bar "in" a bit, where the
bar's tip is closer
to the operator compared to the butt, it improves stifness.
I got a similar made-in-India set along with a Criterion boring head as
a package from MSC many years ago. The shanks on the bars are about the
softest steel I've ever seen, and the brazing is also pretty sloppy. I
figured I'd toss them as I got fed up, but I'm still filing off the
setscrew gouges and resharpening them as required. They don't inspire
any pride of ownership, but cut as well as anything else in the shop.
It was $240 for the set. Go to the above URL to see a picture, and
specs. The equivalent thing bought new from Criterion would end up
close to $1,000.
The bar steel is quite hard near the tips, and the tips have carbide
inserts brazed in. If the tips were correctly shaped, I think that
there would be no problem.
We'll see how HHIP handles this.
I assume that Henry is one of the "H"s in "H&H". I have not
communicated with a Henry yet.
Unless the manufacturer went downhill after getting the order, the buyer
at H&H cannot be an experienced machinist. One look at those boring
bars would have raised fatal suspicions. The tips look crude. As I
said before, it looks like the final grind-to-shape step was omitted.
The catalog says that the manufacturer is in Taiwan, although the boring
head and its box don't say. The cardboard box is marked in both Chinese
hh = henry hiep
he imports a lot of stuff, and also seems to acquire the overstock and
returns from places like Grizzley - I got a nice 8 inch 6 jaw chuck from
him, via e-bay for $125 - buying the backing plate cost me almost as much as
anyway, henry knows stuff, he has one knowlegable staff person (suzzy) who
knows the stock but is not a machinist,and the rest know little (and speak
almost no english)
Hmm. Me, myself, and I?
Sounds like a Chinese or Vietnamese name. No surprise.
Well, this boring bar set was made for H&H - the name is etched into the
side of the head.
I think I talked to Suzy when I ordered the set. Their website flamed
out when I tried to order, so I had to call.
My email complaining that the website flamed out was answered by a
Chris, who seems to be perfectly adept at English.
This same Chris answered my email complaining about the boring bits. No
word so far. I need to ping them.