Good question... and one that really has no "right" answer. Since you are
working with soft brass, alumimum and plastics, the Chinese ones will work
just fine for the first set of cuts.
The real difference between cheap Chinese and more expensive American
tooling tends to be the quality of the steel used, followed by the
tolerances (a chinese 1/4" end mill might be .245 to .255). You can easily
get around this "non standard" sizing by intentionally using a smaller end
mill to cut and make two or more passes --- use a 3/6" end mill and make two
passes to cut a 1/4" groove. A pain in the butt as it takes more time, but
this is a good procedure to make ANY high tolerance cut.
Sharpness ( i.e. resulting in a nice cut) is a function of the steel or
carbide that is used. Be aware that many carbide bits from China are made
from recycled carbide bits -- C2, C4, C6 ... and who knows what the final
mix is. A mixed carbide end mill will make a noticeably worse cut than a
good Micro 100, Kenmetal or other good USA end mill. Sharpness and
durability are not what most Chinese bits are known for.
BUT, they do and will work, and they work surprisingly well for the price.
I have over 100 assorted, cheap chinese end mills that I bought on Ebay for
10.00. Many of the used ones are still usable after pretty good use over
several years , and if they get too dull to cut steel, well, I have a bunch
of new ones rarin' to go. And the dull ones will still cut AL.
You can buy Chinese bits very inexpensively on closeouts everywhere--- I
tend to avoid Harbor Freight as their bits tend to be REALLY junk bits.
(Your mileage may vary... some guys have no problem with HF stuff...)
As for the Titanium coating, it helps initially -- maybe--, but not for
long. The coating is supposed to act as a lubricate, thereby making the cut
easier and smoother. Maybe it is also supposed to provide a "harder"
cutting edge, such that you can mill or drill harder materials, but I have
never found any difference between regular HSS and Ti coated steel. If y
ou need to lubricate, than use a real lubricate likeTapMagic or kerosene for
Al...
(To be blunt, I have often suspected that the Ti coating is often used to
just "cover up" cheap steel, and make the bits or end mills look pretty.
Novices too often fall for what looks good orwhat is hyped to the nth
degree must be good... and this goes back to my first comment.. Chinese
steel is often suspect...)
You also can not resharpen drill bits or end mills with the coating as the
grinding immediately wears the coating off -- as does normal wear and tear.
I have never paid the money for TI, if I was going to pay extra, I always
would go for carbide or Cobalt tooling.
As you said, I would (and did) start with a cheaper set, mill like crazy,
and then buy "real" ones as your needs indicate. Check Ebay, Reliable tool,
MSC, Enco, J &L, et all for closeouts on HSS , carbide or cobalt tooling.
It won't take long (or a lot of money) to get a decent set of tooling.
FWIW, I am a big advocate of carbide for cutting any type of steel and I
tend to use HSS/cobalt for everything else... ALL my lathe tooling now is
carbide and the mill uses anything that works g!
Good luck...
Steve Koschmann
"Walter Harley" wrote in message
...
This might be an unanswerable or simply a religious question, in which
case
I apologize...
Should I get a set of cheap end mills, or should I gradually acquire more
expensive ones? (Or both?)
The context is that I'm a relative newbie to machining, building up my
tool
collection. I don't do large quantities of anything; I generally (but not
always?) work in soft materials like aluminum, brass, and plastic; and my
"mill" is actually a mill/drill. So this is light duty work; but at the
same time, I want the pieces I make to come out nicely, and I know that
with
a dull or imprecise tool there's just no way to cut a straight line or get
a
smooth finish.
One option I've considered is starting with a set of cheapo end mills in
order to get a lot of sizes, and then gradually replacing the ones that I
find myself using most often with better quality. But am I shooting
myself
in the foot to consider cheap end mills at all?
And, a subsidiary question: does TiN make any difference? E.g., I'm
looking
in the Grizzly catalog at all the cheapo plain HSS and TiN-coated HSS
sets,
trying to decide.
Thanks for all the help you guys have been giving me. (Hey, I signed up
for
a continuing-ed machining class at the local technical college this fall!)
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