On Mar 31, 6:54*am, Wes wrote:
Searcher7 wrote:
For example, where would I go online to read the definition(with
images) of what a negative rake is, and whatit does?

Well it generally allows more cutting edges on an insert since no relief is
ground in. *The downside is that cutting forces are increased requiring a
rigid machine. *Light machines tend to do best with positive rake cutting
tools.

If you look at TPU or TPG insert (triangle positive unground) (triangle
positive ground) you will see one side has a larger perimeter than the outer
side, that is due to the rake or clearance the tool needs it can be inclined
in respect to the centerline of your work piece with out rubbing.

Now a TNG has to be declined in respect to the centerline as not to rub. *It
will remove metal but now you need a more rigid machine and your stock is
subjected to heaver forces. *

My worn 10" South Bend can use negative top rake only for light cuts,
which is OK for HSS but apparently not so good for carbide.

Look at a wood plane. *It is an example of positive rake. *The metalworking
equivalent of negative rake would be to flip the blade and run plane
backwards.
Wes

Or a scraper.

Several tool company catalogs have descriptions of carbide types and
geometry. Their recommendations for turning stainless have worked for
me but not the ones for mild or tool steel, so I use HSS.

Jim Wilkins