I don;t know what others do but drilling always seems faster and can
remove more meat for me, so I usually keep stepping up drill sizes
until I either egt up to the largest drill I have or get close to the
size I need and then finish with a boring bar. I would thik a lathe
would be the best for this job as compared to a DP. Once I usually get
a hole thorugh a piece I usually feel better, and things go a lot
faster. I do assume you are step drilling. If not it will make things
a lot easier and quicker.


The bigger the diameter of the boring bar the less deflection you have
so it would stand to reason to use the biggest hole you can bore to
start off with followed by using the biggest boring bar you have.



On Fri, 11 Jul 2003 01:07:05 GMT, "ATP"
wrote:

x-I am boring out two 3" lengths of 1 1/2" round steel bar to 1 1/8 ID. I am
x-working with a South Bend 10" Heavy lathe. I also have a 21" geared head
x-drill press but only a 6" vise to work with.
x-
x-Doing the whole job on the lathe, how large of a hole should I drill to
x-start out with? Is the idea to drill a hole just big enough to start the
x-boring bar?
x-
x-Using the drill press to do the job, what type of bit would be recommended?
x-I drilled holes up to 7/8" in one of the bars today and it was a lengthy
x-process. Even at 150 rpm and a downfeed of 4 thousandths with plenty of oil,
x-the bits would have a tendency to start jamming as soon as they got deep.
x-Then it took plenty of stopping and pulling out to finish the job. Thanks
x-for any advice.
x-

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