... 4.group sizes 12-220 240-1200 #12-1200 1..Chemical and physical Usage:JIS#10-JIS#240(1)It can ... usually used for sandblasting, such as precious metal, the gold, crystal, the glass and cowboy wear. JIS#280-JIS#4000(1 ... ,5-8mm and 180,200,240,280,320F Super Single Crystal Aluminium Oxide