What is the cross-sectional shape of a knife edge file?What is the cross-sectional shape of a knife edge file?Round Square Sharp triangle Half-round Right Answer is: Sharp triangle SOLUTION A knife-edge file has a cross-section resembling a sharp triangle. It is designed for filing narrow grooves and angles above 10°. The acute angle of the “blade” makes these files very versatile for smoothing and deburring tighter internal corners.