The graphite particles and their distribution in {HEAD ~ shape} and {TAIL ~ size} should correspond to class VI/6 of the standard EN ISO 945 1994 or even more refined 
The graphite particles and their distribution in { HEAD ~ shape } and { TAIL ~ size } should correspond to class VI/6 of the standard EN ISO 945 1994 or even more refined
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH