T = triangle
P = Positive 11 degrees relief
G = Ground
U = Utility
C = Ground with closer tolerances than G
3 = size
2 = thickness
1 = 0.1 mm corner radius
2 = 0.2 mm corner radius

I did not look at which endmill you bought, but if it has only one
insert there isn't much benefit from buying the higher tolerance
inserts. Even with multiple inserts, the U utility grade is probably
good enough unless you are really fussy on the finish.

These inserts are very common and you should be able to find them on
Ebay or on sale.

For aluminum you could use ones with more relief. Instead of P in the
second place, you might try D,E,F,OR G.

Dan



Rex B wrote:
I just bought one of these indexible endmills.
http://www.use-enco.com/CGI/INSRIT?PMAKA=324-0105

It uses the following inserts:

TPG/TPU/TPC-321,2

Looks like 6 choices. What is the difference among them, and which
ones
should I buy? I expect to use this for surfacing mild steel and
aluminum. But I have yet to use this minimill so I don't know what I

will end up doing with it
--
- -
Rex Burkheimer
WM Automotive
Fort Worth TX