Tool Geometry & It’s Signature

ATMIYA INSTITUTE OF TECHNOLOGY & SCIENCEMECHANICAL DEPARTMENT3rd SEMESTER – FX Division

Tool Geometry & It’s Signature. (Manufacturing Process-1 – 2131903)

PREPARED BY:Akash Ambaliya (140030119003)Vivek Aghara (140030119001)

Geometry of single point turning tools

• Both material and geometry of the cutting tools play very important roles on their performances in achieving effectiveness, efficiency and overall economy of machining.

• Cutting tools may be classified according to the number of major cutting edges (points) involved as follows:– Single point: e.g., turning tools, shaping, planning and slotting

tools and– boring tools– Double (two) point: e.g., drills– Multipoint (more than two): e.g., milling cutters, broaching tools,

hobs,– gear shaping cutters etc.

Concept of rake angles of cutting tools

• Angle of inclination of rake surface from reference plane.– Rake angle is provided for ease of chip

flow and overall machining. – Rake angle may be positive, or negative

or even zero.

Concept of clearance angles of cutting tools.

• Angle of inclination of clearance or flank surface from the finished surface.

• Clearance angle is essentially provided to avoid rubbing of the tool (flank) with the machined surface which causes loss of energy and damages of both the tool and the job surface.

• Hence, clearance angle is a must and must be positive (3o to 15o depending upon tool-work materials and type of the machining operations like turning, drilling, boring etc.)

Terminology of single point cutting tool

• American National Standards Institute (ANS): A private, non-profit organization that administers and coordinates voluntary standards and systems. Tool signatures and carbide insert classifications are standardized by ANSI.

• Back Rake Angle: If viewed from the side facing the end of the workpiece, it is the angle formed by the face of the tool and a line parallel to the floor. A positive back rake angle tilts the tool face back, and a negative angle tilts it forward and up.


• End Cutting Edge Angle: If viewed from above looking down on the cutting tool, it is the angle formed by the end flank of the tool and a line parallel to the work piece centreline. Increasing the end cutting edge angle tilts the far end of the cutting edge away from the workpiece.

• End Relief Angle: If viewed from the side facing the end of the workpiece, it is the angle formed by the end flank of the tool and a vertical line down to the floor. Increasing the end relief angle tilts the end flank away from the workpiece.


• Face: The flat surface of a single-point tool into which the workpiece rotates during a turning operation. On a typical turning setup, the face of the tool is positioned upwards.

• Flank: A flat surface of a single-point tool that is adjacent to the face of the tool. During turning, the side flank faces the direction that the tool is fed into the workpiece, and the end flank passes over the newly machined surface.

• Lead Angle: A common name for the side cutting edge angle. If a tool holder is built with dimensions that shift the angle of an insert, the lead angle takes this change into consideration.


• Side Rake Angle: If viewed behind the tool down the length of the toolholder, it is the angle formed by the face of the tool and the centreline of the workpiece. A positive side rake angle tilts the tool face down toward the floor, and a negative angle tilts the face up and toward the workpiece.

• Side Relief Angle: If viewed behind the tool down the length of the toolholder, it is the angle formed by the side flank of the tool and a vertical line down to the floor. Increasing the side relief angle tilts the side flank away from the workpiece.


• Nose Radius: The rounded tip on the cutting edge of a single-point tool. The greater the nose radius, the greater the degree of roundness at the tip. A zero degree nose radius creates a sharp point.

• Side Cutting Edge Angle: If viewed from above looking down on the cutting tool, it is the angle formed by the side flank of the tool and a line perpendicular to the workpiece centerline. A positive side cutting edge angle moves the side flank into the cut, and a negative angle moves the side flank out of the cut.

Tool Signature• The numerical code that describes all the key angles of a given

cutting tool. A tool signature may be used for HSS or carbide inserts.

• Convenient way to specify tool angles by use of a standardized abbreviated system is known as tool signature or tool nomenclature.

• It indicates the angles that a tool utilizes during the cut.

• It specifies the active angles of the tool normal to the cutting edge. • This will always be true as long as the tool shank is mounted at

right angles to the work-piece axis.

Tool Signature The seven elements that comprise the signature of a

single point cutting tool can be stated in the following order:

Example: Tool signature 0-7-6-8-15-16-0.81. Back rake angle (0°)2. Side rake angle (7°)3. End relief angle (6°)4. Side relief angle (8°)5. End cutting edge angle (15°)6. Side cutting edge angle (16°)7. Nose radius (0.8 mm)

Thank You…

Engineering

Tool Geometry & It’s Signature