Cutting Tools & Tool Holders.pptx

8/10/2019 Cutting Tools & Tool Holders.pptx

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OBJECTIVES

TO BE ABLE TO IDENTIFY AND KNOW THE PURPOSE OF

THE VARIOUS TOOLBIT ANGLES AND CLEARANCES.

TO BE ABLE TO PREPARE A GRINDER FOR SHARPENING A

GENERAL PURPOSE LATHE TOOLBIT. TO BE ABLE TO GRIND AND SHARPEN A VARIOUS LATHE

TOOLBIT.

TO BE ABLE TO I DENTIFY AND STATE THE PURPOSE OF

THE COMMON LATHE TOOLHOLDRES.


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High Speed Steel(HSS) toolbit

CUTTING TOOLS


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Cement-Carbidelathe toolbit

CUTTING TOOLS


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Toolbitora lathe cutting tool is

generally known by the operationit performs.


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Right cut tool

Left cut tool

Right cut side facing tool

Left cut side facing tool

Curved cutting or round-nose

tool

Knurling tool

Form tool (Radius, Bevel)

Treading tool (External,

internal)

TOOLBIT


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To produce various surfaces, faces and

forms, the cutting edge of the toolbitmust be precisely ground.

The cutting edge must be shaped to the

proper form and then the relieved with

clearance angles to allow the edge to cutinto the metal.


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Pedestal grinder

consist of an electric

motor with a

grinding wheelmounted on each

end of the spindel.

This type of grinding

called offhand

grinding.

GRINDER


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TYPE OF GRINDER

WHEELS

Aluminum oxide are used to grind

carbon and high speed steel (HSS)

toolbits.

Silicon carbide are used to grind

single-pointed cement-carbide cuttingtools.


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GRINDER SAFETY

Always wear approved safety glasses when

operating a grinder.

Always stand to one side of the wheel

when starting a grinder. Never stand in the

line with a grinder wheel.


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GRINDER SAFETY

Allow a new wheel to run for about one

minute before using. If a wheel is going to

break, it will break in the first minute.

Always use a wheel guard which covers at

least one-half of the grinding wheel.


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GRINDER SAFETY

Never run a grinding wheel faster than the

speed recommended on its blotter.

Do not grind on the side of a wheel unlessit is designed for this purpose.


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DRESSING AND TRUING A

WHEEL

Dressingis the process of recondition

the wheel to make cut better.

Truingrefers to shaping a wheel to a

desired shape and to make it grinding

surface run true with it axis.


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TO DRESS AND TRUE A

WHEEL

Adjust the grinder work rest

Wear an approved pair of safety glasses.

Stand to one side of the wheel and then

start the grinder.


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TO DRESS AND TRUE A

WHEEL

Hold the dresser down firmly with its lugs

against the edge of the work rest. Move the dresser across the face of the

wheelin a steady motion for a trial pass.

After each pass, tilt the holder up sligthly toadvance the dresser disks into the wheel.


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TO DRESS AND TRUE A

WHEEL

When the wheel is dressed, stop the

grinder and adjust the work rest to within

1/16in. (1.58 mm) of the wheel face and

tighten securely.


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GRINDING A LATHE TOOLBIT

A lathe tool cuts better if it is provided with

the proper amount of end and side relief.

Too much relief angle (side and end)weakens the toolbit, although it provides a

keener cutting egde.

Too little side or end relief prevents a lathetool from cutting.


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Recommendation factors:

The size and condition of the

lathe

The shape and hardness of theworkpiece

The type of cutting operation

being performes.


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HOW TO GRIND A TOOLBIT?

Hold the toolbit firmly while supporting the

hands on the grinder tool rest.

Tilt the bottom of the toolbit in toward the wheel

and grind the 10side-relief angle and formrequired on the left side of the toolbit.


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Grind until the side cutting edge is about

in. (12.7mm) long and the point is over

about one-fourth the width of the toolbit.

High speed steel toolbits must be cooled

frequently.


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Hold the back end of the toolbit lower than the

point and grind the 15end-relief angle on the

right side. At the same time the cutting edge

should form an angle of from 70 to 80

with theside cutting edge.

Hold the toolbit about 45to the axis of the

wheel, tilt the bottom of the toolbit in, and grind

the 14side rake on the top of the toolbit.


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Grind the side rake the entire length of the side

cutting edge but do not grind the top of the

cutting egde below the top of the toolbit.

Grind a slight radius on the point being sure tokeep the same end and side-relief angles.

Use an oilstone to hone the point and cutting

edge of the toolbit to remove sharp edge,produce a keener cutting edge, and improve its

cutting action.


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A OO O S A


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LATHE TOOLHOLDERS AND

TOOLPOSTS

Method of holding the lathe cutting tool:

In Toolholders, which provide a means of

rigidly holding the cutting tool.

In Toolposts, which provide a means of

holding either a toolholder or a cutting

tool.


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Left-hand offset toolholder is

used to machine work and

cutting from right to left. It is

identified by the letter L.

TOOLHOLDERS


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Straight toolholderit is a

general-purpose toolholderidentified by the letter S.

TOOLHOLDERS


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Right hand offset toolholder

is used for machining work

and cutting from left to right.

Identified by the letter R.

Left and Right hand offset

toolholder accommodate

square toolbits, ranging from

3/16 to in.

TOOLHOLDERS


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Brazed cement Carbide-

tipped toolbits toolholders

are available in five sizes to

accept toolbit shanks from

to 5/8 in, square.

Toolholder hole is parallel to

the base.

TOOLHOLDERS


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Cutting-off or parting tool is

generally used when work is

to be parted off, groove, or

undercut.

1. Solid type toolholders2. Spring type toolholders

CUTTING-OFF TOOLHOLDERS


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A special toolholder with a

cam-shaped cutter ground

to 60is available for

thread cutting,

THREADING TOOLHOLDER


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Boring tool suitable for

heavier work consist of a

boring bar mounted in the

toolholder and a toolbit fitted

on the end of the boring bar.

BORING TOOLHOLDERS


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Heavy-duty boring bar

holder is mounted on the

compound rest and canaccommodate three bars of

different diameters.

BORING TOOLHOLDERS


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Standard (Round) toolpost

provides a means of holding

and adjusting a toolholder ora cutting tool.

TOOLPOSTS


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Turret type toolpost are

designed to hold four cutting

tools, which can be easily

indexed for use as required.

TOOLPOSTS


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Quick change toolpost and

holder are made in different

styles to accommodate

different types of cuttingtools.

TOOLPOSTS

Documents

Cutting Tools & Tool Holders.pptx