My
periodic table poster
is now available!
Silicon nitride ball bearings.
Ball bearings made of extremely hard silicon nitride.
Source:
eBay seller irvineman
Contributor:
Theodore Gray
Acquired:
28 March, 2009
Text Updated:
29 March, 2009
Price:
$4/each
Size:
0.375"
Composition:
Si
3
N
4