An innovative abrasive material for fast grinding and superb surface finishing! GRX consists of aluminum oxide dispersed in a unique elastic bond. Cuts a bit slower than silicon carbide yet imparts a very smooth surface finish – each grit yields a much higher finish than expected. Grinds platinum, gold, silver, steel and aluminum without clogging. Prevents metal surfaces from becoming scorched during processing. Very long-lasting. Mounted on a 3/32" shank, this 1/2" diameter by 1" long bullet of GMX can be easily dressed using an old file. Made in Japan.