I don't have anything more precise and accurate than a ruler to measure
with, but I know that the metal piece that I'm trying to produce will
need to be manufactured with a tolerance for fluctuation from the
desired dimensions of less than a millimeter.

At first, I would like to manufacture as small a number as possible to
make sure that they function as I'm hoping they'll function. Once I
know that they function as I want them to function, I really only need
a small number of them... maybe around 100. If other people find them
helpful, I may want to manufacture more later.

Also, the number that I would like to manufacture all depends on the
cost... if manufacturing 100 costs practically the same as
manufacturing 1000, I'll go for manufacturing 100. But if
manufacturing 1000 is much more costly than manufacturing 100, I'll
have 100 made for now, and make more later if they're needed.

As far as material to construct the part out of, I am really needing in
guidance... perhaps if I describe the purpose of the part that I'm
trying to create it will help.

This metal piece that I'm trying to manufacture is intended to be used
to extend the length of a knob on a musical instrument. This metal
piece will be moved a lot in the course of the use of the instrument,
and will need to remain snugly in place over the metal tab which it fit
over, with no perceptible play. There won't be a lot of force in the
direction that would pull the tab off, but there will be a small
amount.

Ideally, I would like to consult with someone who could manufacture the
part for me, who could also help me work all of the minutia that need
to be worked out to get the part to function as I would like it to.

However, if this isn't available or is prohibitively costly, I can
learn how to work out the minutia myself. In this case, I would need
to either:

a) measure the magnitude and direction of the forces that are typically
applied to this part of the musical instrument, and use those combined
with information about the materials being used to calculate how snug
the metal piece will need to be.

or

b) produce a few prototypes and simply test them to see how well they
function. This would be much easier than option (a), but I don't know
if it will be exceedingly costly.

Any ideas? Thanks very much again

-Max