2. Metal Cutting Process
→ In metal cutting process a sharp edged cutting tool is
made to cut the metal.
→ A tool must be harder than workpiece and it put in a
interference condition with workpiece.
→ By tool force metal comes in compression near the tool
tip, which produces shear-type deformation within the
metal.
→ In the metal cutting process, the tool is wedge-shaped and
has a straight cutting edge.
3. → Basically, There are two type of methods of metal cutting
depending upon the arrangement of the cutting edge with
respect to the direction of relative work-tool motion.
→ There are two types of metal cutting methods as follow:-
1. Orthogonal Cutting & Two Dimensional Cutting
2. Oblique Cutting & Three Dimensional Cutting
4. 1. Orthogonal Cutting
→ The essential features of orthogonal or two dimensional cutting
are as under.
• The cutting edge of the tool is perpendicular to the cutting
velocity vector.
• The direction of chip flow velocity is normal to the cutting edge.
• The cutting edge clear the width of the workpiece on either
ends. There is no side flow.
• Only two components of the cutting forces are acting on tool,
which are perpendicular to each other and can be represented
in a plane. (x,y)
5. • Tool is
perfectly sharp
and contacts
the chip on
rakeface only.
e.g Lathe cut
off opstain,
straight
Milling.
6. 2. Oblique Cutting
→ The essential features of orthogonal or two dimensional
cutting are as under.
• The cutting edge is inclined at an angle “ i ” with the normal to
the cutting velocity vector.
• The chip flow on tool face making an angle with the normal on
the cutting edge. The angle being measured in the plane of the
tool face.
• The cutting edge may or may not clear the width of the
workpiece.
• Three components of the cutting forces are acting on the cutting
edge. The components are mutually perpendicular to each
other.
7. • The tool may or may
not generate a
surface parallel to
workface.
• The maximum chip
thickness may not
occur at the middle.
• Frequently, more
than one cutting
edges are in action.
e.g Faming, Milling.
