... resistant,prevent rust,no burr Bottom hole with angle upper slotter blade :1):Hardness:HRC 61-622)Thickness: ... machine etc.7)Commodity list:: CommodityProjectBottom hole with angle upper slotter bladeMaterialSKD11,D2,DC53Tooth shapetriangle,cavernousHole positionupper,bottomDegree15-90 ... ,ODM etc.8)Advantages: Bottom hole with angle upper slotter blade are suitable for all kinds of corrugatedcardboard ...