Following are the two methods of metal cutting depending upon the arrangement of cutting edge with respect to the direction of tool travel:
1. Orthogonal cutting or two dimensional cutting.
In orthogonal cutting, the cutting edge of the tool is perpendicular to the direction of tool travel. The cutting edge clears the width of the workpiece on either ends. The chip flows over the tool face and the direction of the chip flow velocity is normal to the cutting edge. The maximum chip thickness occurs at the middle. In orthogonal cutting, the shear angle is the angle between the rake face and the shear plane.
2. Oblique cutting or three dimensional cutting.
In oblique cutting, the cutting edge of the tool is inclined at an angle less than 90° to the direction of tool travel. Frequently, more than one cutting edges are in action. The cutting edge may not clear the width of the work piece. The chip flows
on the tool face at an angle less than 90° with the normal on the cutting edge. The maximum chip thickness may not occur at the middle.
2) In orthogonal cutting, the shear angle is the angle between the
Rake face and the shear plane
Related Diploma CET Mechanical Question Paper - 2018 with Answer Key
A plane surface
Facing Operation. Facing is the process of removing metal from the end of a workpiece to produce a flat surface. Most often, the workpiece is cylindrical, but using a 4-jaw chuck you can face rectangular or odd-shaped work to form cubes and other non-cylindrical shapes
Any odd-shaped workpiece to locate the axis of rotation
Faceplates are used to hold work that is too large or of such a shape that it cannot be held in a chuck or between centers. Faceplates are equipped with several slots to permit the use of bolts to secure the work, so that the axis of the workpiece may be aligned with the lathe centers. When work is mounted off – center, a counterbalance should be fastened to the faceplate to prevent imbalance and the resultant vibrations when the lathe is in operation.
Boring
Boring Boring is an operation of enlarging a hole that has already been drilled. Boring is done by a single point cutting tool.
Trepanning
Trepanning is an operation of producing a hole by removing metal along the circumference of a hollow cutting tool.
