Yes, but for the number of pinhole users, the small production would be
extremely expensive. A better, less expensive method would be the use of a
laser drill. This would provide a perfect pinhole, no burrs, etc., and a
person needing the work done could probably beg it from someone who has the
instrument (such as an opthalmologist).
If I wanted a perfect pinhole, that's what I would do. Several years ago, I
gave a lecture on "The Future of Photography" at the U of Mass, and noted
that one ideal item every photographer would like is a universal
focal-length lens. During the discussion period an attendee reminded me that
a pinhole lens fits that description! With a superfast recording medium
(film or electronic) the small f-stop wouldn't be a big handicap; of course,
the focus diffraction could be. <<sil>>