Hi all, I want pay someone to produce multiple copies of a piece of
metal in a certain shape. This piece of metal will be small (about 1 cm
x 1 cm x 1.5 millimeters.) It will have a small slit in it, which is
meant to fit snugly over another piece of metal, so the specified
dimensions of the metal piece being produced must be reproduced with a
very high amount of precision and accuracy.

I am pretty new and clueless to the world of metalworking, but I have a
background in the physical sciences and math, and am a fast learner.
Can anyone suggest a production method for this piece of metal that I'm
talking about? Perhaps die casting?

If anyone has any introduction to metalworking websites/documents that
they think would be helpful, I would greatly appreaciate any
suggestions here as well