Single point cutting tools are commonly used in
lathe,palners,shapers machine for cutting operation. These
tools are classified as left handed and right handed. A tool
is said to be right handed if their cutting egde is on right
side when tool is viewed from the point end.
|Single point cutting tool|
Terminology or Nomenclature of Single Point Cutting
This specification is according to American Standards
Association (ASN) Systems.
Terminology or Nomenclature of Single Point
1. Back rake angle
It measures downward slope of the cutting tool from the nose
to the rear along the longitudinal axis. It guides direction
of chip flow and protects cutting tool point. Softer the
material, greater should be the positive rake angle.
Back rake angle may be postive negative or neutral.
2) Side rake angle
It measures slope of the top surface of the tool to the side
in direction perpendicular to the longitudinal axis.
The angle also guides directions of chip away from the job.
The amount by which a chip is bent depends upon this
angle. When side rack angle increases,magnitude of chip
bending decreases. Smoother surface furnish is produced by
larger side rake angle.
3) Side relief angle
This angle is between flank of the tool and a plane normal to
the base just under the side cutting edge. This angle allows
the tool to fed sideways into the job in order to cut the
work material without rubbing. When side relief ange is very
small,the tool will rub against the job and therefore it will
get overheated and become blunt and the surface finish
obtained will be poor.
4) End relief Angle:
This is angle between plane normal to the base and flank.
This angle prevents the rubbing between work materials and
cutting tool. Very large end relief angle will lead to
the breaking of the egde. If angle is too small it will rub
on the job leading poor surface finish. This angle may
varies from 6 to 10 degree
5) Eng cutting edge angle
It is the angle between minor flank and a plane perpendicular
to the side of shank. This ad angle serves as a relief angle
allowing a small section of the end cutting edge to contract
the machined surface. This angle usually varies from 5 to 15
6) Side cutting edge angle
This is the angle between side cutting edge and longitudinal
axis of the tool. It controls the direction of chips flow and
avoid the formation of build up edge. This angle also
distributes the cutting forces and heat produced over larger
It increase finish and strengthen cutting tip of the tool.
Smaller radii produce smoother surface finish, Small radii is
more suitable for thin cross section of works.