[Phono-L] Coin machine or jukebox needles?

[Chris Kocsis]

Can anyone give me the lowdown on jukebox needles?  I bought some new 
old stock Cole's coin machine needles with osmium tips.  The package 
says the needle lasts many plays and doesn't have to be rotated.  I'm 
also curious about the shape of the needle.  A couple of millimeters up 
from the point, the metal is flattened into a pointed oval like a cobra 
head and then resumes being cylindrical.  What is that for?

Osmium is nearly as hard as tungsten and I've seen some references to 
people cutting their own needles from tungsten wire and forming the 
point by rubbing the cut end in a record groove while rotating it (which 
seems astonishing).

Is such hardness a good idea in a needle, or does it cause excessive 
record wear? 

If these jukebox needles are safe to use, how do I tell when it's time 
to change one?

Best regards,

Chris