I'm looking at R8 carbide indexable end mills from CDCO to use for
cleaning up rusty stock and squaring up stock. One says it uses
tpg-32 inserts. Are those the same as tpg-322?

Another alternative is a similar 2.5" indexable end mill, which uses
a different insert. SPG422 carbide Positive rake, 15 Degree lead angle
I have a Bridgeport with the 2J head. Which of the two is more likely
to give a good finish on hot and cold rolled steel?

What difference does the positive rake and 15º lead angle make?

Here's a link to the 2" one
http://www.cdcotools.com/item.php?itemid=126

Here's the link to the 2.5" one
http://www.cdcotools.com/item.php?itemid=471

RWL