lathe tools and drilling machine

INT 252 Explorations Studio: Fabrication & Development

Assignment 9 : Metal summary Samira Hanafi swilimId NUMBER: 201310025 Instructor: Dr. Adnan HusneinDate of submission: 28-4-2016

- Lathe is a machine, which removes the metal from a piece of work to the required shape &size. - Single point tool : is the cutting tool used on lathe and it has only a single cutting edge or point at one end of its body. The point is wedge shaped portion, forms the cutting part of the tool.

4/30/2016Lathe tools 6.4.9

Lathe Tools

4/30/2016Lathe tools 6.4.9

Nomenclature of a lathe tool

Solid Forged tool

- The single point cutting tool has only one cutting point or edge. - These tools used for turning, boring, shaping or planning

operations. These tools used on lathe, boring and shaper machines.

- Made from high carbon steel or high speed.

- made of high speed steel, stellite or cemented carbide , which can be brazed on high carbon steel shank and tools this made

called brazed tools

Cutting bits or tips or inserts

4/30/2016Lathe tools 6.4.9

Types of lathe tools

Generating external surfaces Generating internal surfaces

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Nomenclature of single point cutting tool

A single point cutting tool consists of a sharpened cutting part and the shank and main parts or elements which are:

Single point cutting tool

Cutting EdgerakeNose

BaseHeelFlankFACEshank

It is the main body of the tool.

The surface on which the chip slides is called the face of the tool.

The surface or surfaces below the adjacent to the cutting edge is called flank of the tool.



It is the point where the side cutting edge and end cutting edge intersect.

It is the edge on the face of the tool which removes the material from the work piece. The cutting edge consists of the side cutting edge(major cutting edge) and cutting edge(minor cutting edge) and the nose.

refers To the slope of the tool top away from the cutting edge.

4/30/2016Lathe tools 6.4.9

Nomenclature of single point cutting tool

A single point cutting tool consists of a sharpened cutting part and the shank and main parts or elements which are:

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Cutting tool materials

Ideal Characteristics

Hot hardnessWear

resistanceToughness

Coefficient of friction

Cost

Keeps the tool material hard enough even at higher temperature.

The material tool should withstand wear due to the rubbing of chips on the tool.

Should withstand to shocks and vibration during cutting of metals.

Should remain low at the chip tool interface to minimize tool wear.

Should remain low at the chip tool interface to minimize tool wear.

4/30/2016Lathe tools 6.4.9

Tool LIFE

Is the time for which a tool will operate satisfactorily until it gets dulled or blunt.

Types of tool wears

Creating crumbling of the cutting

edge

Hardness loss or

fracture of the tool

Reasons of tool fail

Cutting speed

Feed depth of cut

Use of cutting fluids or coolants.

Factors affecting tool life

Note : proper coolants, lower cutting speed, feed and depth of cut help increasing the tool life.

4/30/2016Cutting fluids 6.4.10

Cutting Fluids

Essential in metal-cutting operations to reduce heat and friction

Sources of heat generation in metal cutting

Friction heat Heat of chip distortion Heat of deformation

Slipping of metal grains under pressure of cutting.

Internal friction due to the curling of chips during cutting.

Generates between chip and tool interface.

PURPOSE OF USING

Reducing friction between tool and job.

Reducing various types of wears.

Increasing tool life.

Help easy removal of chips away from tool tip.

PREMIT THE USE OF HIGHER CUTTING SPEED AND DEPTH WITHOUT AFFECTING TOOL LIFE

REDUCING MACHING TIME AND COST.


Cutting Fluids

Heat find its way into one of three places

Act as disposableheat sink

Too much, cutting edgewill break down rapidly, reducing tool life

Too much, workwill expand


Cutting Fluids

Heat Dissipation

• Ideally most heat taken off in chips

• Indicated by change in chip color as heat causes chips to oxidize

• Cutting fluids assist taking away heat

• Can dissipate at least 50% of heat created during machining


Cutting Fluids

Characteristics of a Good Cutting Fluid

Good cooling capacityGood lubricating

qualitiesResistance to

rancidityRelatively

low viscosity

Stability (long life) Rust resistance Nontoxic TransparentNon-

flammable


Cutting Fluids


Are available in various types

Gaseous type cutting fluidsSoluble oils or emulsionsCutting oils

Cutting oils

For machining ferrous metals.

Active Inactive

For machining Non-ferrous metals.


Cutting Fluids




Soluble oils or emulsions

Mineral oils containing soap like material that makes them soluble in water and causes them to adhere to work piece.

Good cooling and lubricating qualities Used at high cutting speeds, low cutting pressures


Cutting Fluids




Gaseous type cutting fluids

Air or carbon-di-oxide are more common.

Air Carbon-di-oxide

under pressure is quite effective when used in {subzero cooled state}.

use in machining low machinable and high strength thermal rsistance.

4/30/2016Drilling Machine 6.5

Drilling machine

Drilling is the operation of producing circular hole in the work-piece by using a rotating cutter called DRILL.

The machine used for drilling is called drilling machine.

The drilling operation can also be accomplished in lathe, in which the drill is held in tailstock and the work is held by the chuck.

The most common drill used is the twist drill.


Drilling machine

Drills types

Flat or spade drill Straight fluted drill Twist drill

Flat or spade drill

Spade drills or flat drills are similar to gun drills in that the cutting end is a flat blade with two cutting lips.

Spade drills are usually clamped in a holder and are easily replaced or re sharpened.

They are available in a wide range of sizes from very small micro drills to drills up to 300mm in diameter.

Some of the smaller spade drills have replaceable carbide inserts.


Drilling machine

Drills types


Straight fluted drill

Recommended in drilling soft materials such as brass, coper , aluminum , bronze and other softer plastic materials.

Straight flute prevent drill from drawing itself into material while cutting.


Drilling machine

Drills types


Twist drill

The twist drill is made from High Speed Steel, tempered to give maximum hardness throughout the parallel cutting portion.

Flutes are incorporated to carry away the chips of metal and the outside surface is relieved to produce a cutting edge along the leading side of each flute.

4/30/2016Drilling Machine operations 6.5.1

Drilling machine Operations

Operations include

Reaming Boring Counter boring Counter sinking Spot facing Tapping

Reaming

It is a process of smoothing the surface of drilled holes with a tool.

Tool is called as reamer. Initially a hole is drilled slightly

smaller in size. Drill is replaced by reamer. Speed is reduced to half that of the

drilling.



Operations include


Boring

It is process carried on a drilling machine to increase the size of an already drilled hole.

Initially a hole is drilled to the nearest size and using a boring tool the size of the hole is increased.



Operations include


Counter boring

This process involves increasing the size of a hole at only one end.

Cutting tool will have a small cylindrical portion called pilot.

Cutting speed = two-thirds of the drilling speed for the same hole.



Operations include


Counter sinking

This is an operation of making the end of a hole into a conical shape.

Cutting speed = half of the cutting speed of drilling for same hole.



Operations include


Spot facing

It is a finishing operation to produce flat round surface usually around a drilled hole, for proper seating of bolt head or nut.

It is done using a special spot facing tool.



Operations include


Tapping

Process of cutting internal threads with a thread tool called as tap.

Tap is a fluted threaded tool used for cutting internal thread

Cutting speed is very slow.



Operations include


4/30/2016Types of Drilling Machine 6.5.2

Types of Drilling machine

It is the simplest and accurate machine used in production shop.

The work piece is held stationary ie. Clamped in position and the drill rotates to make a hole.

Types :-a) Based on construction:

Portable, Sensitive,Radial, up-right, Gang, Multi-spindle

b)Based on Feed:Hand and Power driven


Types of Drilling machineCutting Fluids

Based on construction

Portable drilling machine

Is a handy powered drilling tool capable of being easily taken to work sites. It has the capability and flexibility of drilling holes in odd situations. These are usually available up to 15mm drill capacity.




Bench or Sensitive Drilling Machine

These are light duty machines used in small workshops. called Sensitive drilling machines because of its accurate and well balanced

spindle. Drill holes from 1.5 to 15mm (up to 13 to 16 mm)




Bench or Sensitive Drilling Machine

Vertical main column

Base

Moving drill head

Work table

Electric motor

Variable speed gear box

and spindle feed

mechanism.




Up-Right Drilling Machine

Drill holes up to 40mm

Similar to bench drilling except

that it is larger in size, robust in

design and it is used for heavier

work.




Radial Drilling Machine

These are heavy duty and versatile

drilling machine used to perform

drilling operate on large and heavy

work piece.

Holes up to 50 mm are easily drilled

on theses machines.




Radial Drilling Machine

Heavy base

Vertical column

Horizontal arm

Drilling head

lathe tools and drilling machine

Engineering