I have hammer from beryllium copper (actually a speck of aloy was sent to ASA analysis to confirm that).
This hammer is rarely used (or actually not used because it seems precious). Anyway usual steel hammer works as good. Such tools are of use on oil platforms and they are unknown to cause disease.
One can buy few pieces of beryllium, for example here: http://luciteria.com/elements-for-sale/buy-beryllium
There are bike frames made of beryllium, $30000 a piece. Advantage – light weight.
I would take care with this metal. Heating can produce fine particles of oxide (BeO) and these are really bad idea for one's lungs. This material is one of very few, which I consider "dangerous chemical". Would prefer to work with cadmium, thallium, arsenic or uranium rather than with that.
Beryllium copper is fine but I would hesitate to braze it and if I have to then job would be *certainly* done on open air and I would use professional dust filtering mask.
Edited By Martin Dowing on 23/02/2018 20:12:22