Method to machine a metal work piece by turning

A method to form a surface on a metal work piece comprising:

• a first machining step of providing a turning insert including a first cutting edge, a second cutting edge and a convex nose cutting edge connecting the first and second cutting edges, and selecting a nose angle formed between the first and second cutting edges to be less than or equal to 85°;
• arranging the turning insert such that the turning insert includes a top surface, an opposite bottom surface, wherein a reference plane is located parallel to and between the top surface and the bottom surface;
• arranging the first cutting edge such that the distance from the first cutting edge to the reference plane decreases as a distance from the nose cutting edge increases;
• arranging the orientation of the second cutting edge such that it forms a back clearance angle of more than 90° in a feed direction;
• positioning all parts of the turning insert ahead of the nose cutting edge in the feed direction;
• rotating the metal work piece around a rotational axis in a first direction;
• and
• moving the turning insert in a direction parallel to or at an angle less than 45° relative to the rotational axis such that the first cutting edge is active and ahead of the nose cutting edge in the feed direction and such that the surface at least partly is formed by the nose cutting edge.

A method to form a surface on a metal work piece comprising:

• a first machining step of providing a turning insert including a first cutting edge, a second cutting edge and a convex nose cutting edge connecting the first and second cutting edges, and selecting a nose angle formed between the first and second cutting edges to be less than or equal to 85°;
• providing a turning tool including the turning insert and a tool body, the tool body having a front end and a rear end, a main extension along a longitudinal axis extending from the front end to the rear end, and an insert seat formed in the front end in which the turning insert is mountable;
• arranging the orientation of the second cutting edge such that it forms a back clearance angle of more than 90° in a feed direction;
• rotating the metal work piece around a rotational axis in a first direction;
• moving the turning insert in a direction parallel to or at an angle less than 45° relative to the rotational axis such that the first cutting edge is active and ahead of the nose cutting edge in the feed direction and such that the surface at least partly is formed by the nose cutting edge;
• and
• setting the longitudinal axis of the tool body at an angle greater than zero but less than or equal to 90° relative to the rotational axis of the metal work piece.

A method to form a surface on a metal work piece comprising:

• a first machining step of providing a turning insert including a first cutting edge, a second cutting edge and a convex nose cutting edge connecting the first and second cutting edges, and selecting a nose angle formed between the first and second cutting edges to be less than or equal to 85°;
• arranging the turning insert such that the turning insert includes a top surface, an opposite bottom surface, wherein a reference plane is located parallel to and between the top surface and the bottom surface;
• arranging the first cutting edge such that the distance from the first cutting edge to the reference plane decreases as a distance from the nose cutting edge increases;
• arranging the orientation of the second cutting edge such that it forms a back clearance angle of more than 90° in a feed direction;
• rotating the metal work piece around a rotational axis in a first direction;
• and
• moving the turning insert in a direction parallel to or at an angle less than 45° relative to the rotational axis such that the first cutting edge is active and ahead of the nose cutting edge in the feed direction and such that the surface at least partly is formed by the nose cutting edge.