Place of Origin : - Any -,China
GH:60~65HRC
GP:42~52HRC
GL:53~60HRC
Hardness: GH Steel Grit Has High Hardness, Grayish White Color, Hardness 60-65HRC; GP Steel Grit Has Black-blue Color, Hardness 42-52HRC; GL Steel Grit Has A Bluish Color, Hardness 53-60HRC.