Basic of metal cutting process

1. Topic-Basics of metal cutting process
by
Mr. Binit kumar
Assistant Prof., ME department
GLBITM, Greater Noida

2. Metal Cutting
Define machining process?
Machining is an essential process of finishing by which jobs are
produced to the desired dimensions and surface finish by gradually
removing the excess material from the performed blank in the form of
chip with the help of cutting tool.
Machining is an material removal process.
fig 1- Surface grinding operation

3. Single and multi-point cutting
Single point cutting Multi-point cutting
The cutting tools contains only one
cutting edge
The cutting tools contains more than one
cutting edge
The operation Performed is Turning ,
facing etc
The operation Performed Gear cutting,
knurling and Broaching etc
Single point cutting tool used in machines
like Lathe, shaper , Planar
Multi point cutting tool used in machines
likes milling , Grinding .
Shorter tool life Longer tool life
Cutting temperature is high Here cutting temperature is slightly low

4. Orthogonal cutting
 Orthogonal cutting is a type of metal cutting in which the cutting
edge of wedge shape cutting tool is perpendicular to the direction of
tool motion.
In this cutting the cutting edge is wider than width of cut.
This cutting is also known as 2D cutting because the force develop
during cutting can be plot on a plane or can be represent by 2D
coordinate.
Fig2- Orthogonal cutting process
tc = Chip thickness
to= Depth of cut

5. Tool wear and tool life
Tool wear Describes gradual failure of cutting tools due to
regular operations.
Tool wear causes the tool to lose its original shape- Ineffective
cutting

6. TOOL LIFE
Tool no longer performs desired function – failed
Useful life of a tool expressed in terms of time from start of a cut to termination point
(defined by failure criterion). Sometimes also expressed in terms of no. Of the parts
machined.
TAYLOR’S TOOL LIFE EQUATION
where V = cutting speed (m/min), T = tool life; and n and C are parameters whose
values depend on feed, depth of cut, work materials, tool material, and tool life
criterion used.

7. Cutting tool materials
Cutting tool materials must be harder than the material
of the work piece, even at high temperatures during the
process.
Cutting tool material must possess high wear
resistance, good bending strength and have sufficient
toughness,

8. Properties for tool materials

9. Cutting fluid
Cutting fluid is a type of Coolant and lubricant
designed specifically for metal working processes, such
as machining.
There are various kinds of cutting fluids, which include
oils, oil-water , pastes, gels, aerosols (mists), and air or
other gases.
Cutting fluid are made from petroleum distillates, water
and air, or other raw ingredients. Depending on context
and on which type of cutting fluid is being considered, it
may be referred to as cutting fluid, cutting oil, cutting
compound, coolant, or lubricant.

10. Machinability
Machinability is the ease with which a metal can
be cut (machined) permitting the removal of the
material with a satisfactory finish at low cost.
Materials with good machinability require little
power to cut, can be cut quickly, easily obtain a
good finish, and do not wear the tooling much.
The factors that typically improve a material's
performance often degrade its machinability.

11. Reference
Manufacturing science, by Amitabh Ghosh
and Asok kumar malik,

12. Thank you