In orthogonal cutting, the tool approaches the work piece with its cutting edge parallel to the uncut surface and at right angles to the direction of cutting. Thus tool approach angle and cutting edge inclination are Zero. This type of cutting is also known as Two-dimensional Cutting.
Orthogonal Cutting assumptions
- The tool is perfectly sharp and there is no contact along the clearance face.
- The Cutting edge of the tool remains normal to the direction of tool feed or work feed.
- The direction of the chip flow velocity is normal to the cutting edge of the tool.
- The cutting edge is a straight line, extending perpendicular to the direction of motion and generates a plane surface as the work moves past it.
- The chip does not flow to either side.
- The depth of cut is constant.
- Width of the tool is greater than that of work piece
- The work moves relative to the tool with uniform velocity.
- A continuous chip is produced with no built-up edge.
Oblique cutting assumptions
- The cutting edge of the tool always remains inclined at an acute angle to the direction of tool feed or work feed
- The direction of the chip flow velocity is at an angle ‘β’ with the normal to the cutting edge of the tool. The angle is known as Chip flow Angle.
- The cutting edge of the tool is inclined at an angle ‘i’ with the normal to the direction of work feed or tool feed i.e., the velocity Vc
- Three mutually perpendicular components of Cutting Forces act at the cutting edge of the tool.
- The cutting edge may or may not be longer than the width of the cut.