The pencil with pencil type hardness tester can test all kinds of paint film hardness (ink, primer, paint, coating, elastic paint, electroplating paint,UV oil, etc.) Pencil hardness grade: from soft to hard (6B, 5B, 4B, 3B, 2B, B, HB, F, H, 2H, 3H, 4H, 5H, 6H, 7H, 8H, 9H, a total of 17 specifications)