The MSC catalog has a pretty good tutorial on the subject.
I don't know whether the online version has the same detail, but you
can look: www.mscdirect.com, I think.
I wouldn't spend much time on negative rake inserts unless you have a
pretty solid lathe. Remember that you have to force the cutting tool
into the work to get it to cut. If you are "forcing" a positive rake
insert into the work, the included angle of the edge is less than 90
degrees (somewhat acute). A negative rake cutting edge is has a 90
degree angle or more. Less acute, (less "sharp") = more pressure
required to get it to cut = more bending of the the machine before tool
gets pushed into the work = less precision of setting a cut.
Try taking a 1/2 thou cut with even a TPU (7° positive rake) insert.
Then try again with a 12° HSS tool. See which one takes of the metal.
If they both do, then you can think about "N".

I know because I have an Atlas 10" lathe,
Pete Stanaitis
---------------------

Searcher7 wrote:

On Mar 28, 10:10 am, Wes wrote:

wrote:

What I really wanted to start with was the 16N, but there is no cigar
for second place:http://cgi.ebay.com/ws/eBayISAPI.dll...m=250227734204
(If it wasn't for the high bidder, I would have paid just over $60 for
it). :-(

Anyway, since most of my machining links went with the big PC crash of
2006, I was hoping that someone could direct me to some sites that
explain the characteristics and features of various indexable tooling.

I just have to learn more about it. :-)

http://www.aloris.com/pdfs/2006_Aloris_Catalog.pdf

Have you looked through their catalog? Link above.

Wes


I downloaded that catalog a week ago.

But what I'm looking for is a tutorial.

For example, where would I go online to read the definition(with
images) of what a negative rake is, and whatit does?

Thanks.

Darren Harris
Staten Island, New York.