A method for forming a profile having at least three consecutive concave surfaces in an internal surface of a metal part includes piercing the metal part to create at least three consecutive concave surfaces. First, second and third concave surfaces respectively have first, second and third radii of curvature. The second concave surface is between the first and third concave surfaces. The second radius of curvature is different from the first and third radii of curvature. The method includes carburizing the metal part, grinding the second concave surface, and linear broaching the first and third concave surfaces with an abrasive-covered broach. A method for forming a groove in a surface of a metal part includes broaching the surface to create a groove having a groove surface, carburizing the metal part, and broaching a portion of the groove surface with an abrasive-covered broach after carburizing the metal part.