Optimum for grinding process of hardened materials such as carbide alloy, hardened steel, ceramics, glass, reinforced plastic.Sharpness of diamond abrasive grains will last until the end.The blade metal has elasticity and fits the work material.Optimum for burring rough cutting/rigidity processed goods.Type:8 Piece SetShape:Half-round (width) 9.5 x (thickness) 3.0Total Length (mm):200Blade Length (mm):70Handle Shape:HandType for Iron Work (#140)8 pieces set, 10 pieces set is a common name expressing the size of a file, it does not mean that it actually contains 5 pieces, 8 pieces, 10 pieces, 12 pieces.