Positive Rake Carbide Inserts - Precision Finishing Bits. Positive Rake carbide inserts are designed for precision finishing on modern brake lathes. Featuring an aggressive positive rake angle, these bits shear metal cleanly to reduce heat and prevent surface tearing, making them ideal for high-carbon rotors and sensitive composite materials. Precision-ground with a.017 radius to provide a superior, non-directional finish that minimizes break-in time for new pads. Technical Features: Clean Shearing Action: The positive rake geometry cuts with less pressure than standard bits, resulting in a cooler cut and a smoother, non-directional surface finish. Industrial Carbide: Built from dense, wear-resistant carbide that holds a sharp edge longer during high-speed finishing passes. 3-Point Face: T.