On Wed, 21 Dec 2005 23:18:03 -0500, "Robin S."
wrote:


"Bill Schwab" wrote in message
link.net...
Hello all,

I have been looking at $80-100 import boring head/bar sets. For that
money, I would not expect to start rebuilding V12 engines, but it would
hopefully teach me a little and tolerate abuse as an adjustable hole saw.
Is that a reasonable expection?


We had some Chinese boring heads at school. You could easily hit a hole to
.001", closer if you take your time.

I would recommend replacing all the fasteners (basically the setscrews for
clamping the tool, and the slide) before use. Correctly adjusting the
tension on the clamping screws for the slide is important for good results
and bad hardware makes your life *difficult*.

YMMV.

Regards,

Robin

Hey Bill,

What Robin says about the lock screws, for sure if it's an
"off-shore"!!

There are usually two or three spec measurements given in the adverts.
One is the accuracy of course, one is the "bore size" capability or
the effective "adjustment" range, and then the one to note is the
measurement as to the size shank of the boring bar to be held, usually
from 3/8 to 1" size. That last one is a little harder to suggest
what's right for you, and best you have a look in your bin of boring
bars and see what diameters are good for you. You can sleeve a small
one into a big hole if you need to, so consider that too.
Most boring heads have both a horizontal hole, and a vertical hole,
and some have two or three verticals, so covering a broader range of
work-hole diameters.
Some boring heads are called "boring-facing heads", and have a
capability to advance the boring size outwards at each revolution,
allowing "facing" or trepanning.
Drop into a dealer, and look at the selections.

Take care.

Brian Lawson,
Bothwell, Ontario.