Questions regarding sintering of metals

I hope someone is familiar with sintering processes well enough to
explain to me a little about the limitations of sintering. I have a
sintered component in my hand that's basically rectangular (consistent
thickness) with a slot through the length of the center of the rectangle
and one end of the rectangle sort of rounded and with some very sharp
little points (edges, actually) on the outside of it. These sharps are
not created by post-processing, but in the sintering mold itself.
However, there seems to be some limitations that the sintering shop (in
Taiwan) has regarding depth and number of the sharps. But between them
not speaking English well and me not speaking Chinese (at all) I can't
get very much more than "we can't do it" out of 'em. No real idea WHY
they can't do it. Anybody willing to strike up a "conversation" on the
subject?
TIA
Mark 'Sporky' Stapleton
Charlotte, North Carolina
(remove / replace MUNGE elements in my email address if you want to
reply directly -- but I'll check back in this newsgroup)