Cutting Tools, Coolant, and Cutting Conditions (Week 6)

Question 1

Describe the Lathe Operation :

Turning

Answer 1

Creates a varying diameter over a linear distance.

Question 2

Describe the Lathe Operation :

Facing

Answer 2

Cut a flat surface perpendicular to the work piece’s rotational axis.

Question 3

Describe the Lathe Operation :

Parting

Answer 3

Separates the work piece from the main stock.

Question 4

Describe the Lathe Operation :

Form Cutting

Answer 4

Creates a concave or convex radii with a single tool.

Question 5

Describe the Lathe Operation :

Boring

Answer 5

The process of enlarging and truing up an already existing hole.

Question 6

Describe the Lathe Operation :

Drilling

Answer 6

Creates a hole with a multi-point cutting tool.

Question 7

Describe the Lathe Operation :

Thread Cutting

Answer 7

Creates a spiral tool path with a specific TPI or pitch.

Question 8

Describe the Lathe Operation :

Knurling

Answer 8

Increases the surface for press fitting.

Question 9

What are the most commonly used cutting tools?

Answer 9

-High-speed steel

-Carbide Cutting Tools

-Diamond

-Cubic boron nitride

-Ceramics

Question 10

High-speed steel is a tool steel with high hardness, ________________, and ________________ by adding more alloy elements such as tungsten, molybdenum, chromium, and Vanadium.

Answer 10

High-speed steel is a tool steel with high hardness, [high wear resistance], and [high heat resistance] by adding more alloy elements such as tungsten, molybdenum, chromium, and Vanadium.

Question 11

Carbide Cutting Tools can machine metals at speeds that cause cutting edge to become red hot without losing harness. It has a series of excellent properties such as ______________, ______________, ______________, ______________, and ______________.

Answer 11

Carbide Cutting Tools can machine metals at speeds that cause cutting edge to become red hot without losing harness. It has a series of excellent properties such as [high hardness], [wear resistance], [good strength and toughness], [heat resistance], and [corrosion resistance].

Question 12

When to Use Spot Drills vs Center Drills?

Answer 12

To guarantee that the hole is precisely situated so that the twist drill does not deflect and “walk” off-center.

Spot drill is a better choice than a Center drill.

Question 13

Do we need to use coolant? Why?

Answer 13

Yes

• Cutting fluids help to improve the surface finish of the workpiece by flushing away chips and reducing built-up edges
• Cutting fluids are used to reduce friction, through lubrication and prevents rust and corrosion,
• Reduces the friction between the tool and the workpiece, diminishing the heat generation and cutting forces, and in consequence, improving tool life and surface quality.

Question 14

What are the 6 main Cutting Conditions?

Answer 14

1. Cutting Speed/Cutting velocity
2. Feed
3. Depth of Cut
4. Type of materials
5. Tool shape-Cutter/ Inserts
6. Coolant condition

Question 15

What are 3 things Cutting Conditions affect?

Answer 15

1. Ra- Surface Roughness,
2. MRR (Material removal rate)
3. Tool life

Question 16

What is cutting speed/velocity (surface speed)?

Answer 16

It is the tangential velocity of either the rotating workpiece or the rotating cutting tool.

It is measured by the unit—meters per minute (m/min or ft/min) and designated by Vc

Question 17

What is Spindle Speed?

Answer 17

The number of revolutions per minute (rpm) that is made by the cutting tool of a machine.

Defined in revolutions per minute (rpm) and found by dividing the cutting speed by the circumference of the workpiece (wp).

Question 18

What is the lathe Feed?

Answer 18

Feed – The distance advanced for every rotation of workpiece (mm/rev) spindle

Feed of engine lathe dependent on speed of lead screw for feed rod – Speed controlled by change gears in quick-change gearbox

Question 19

What are some Important factors that influence speeds feeds, and depth of cut?

Answer 19

1. Type and hardness of work material
2. Grade and shape of cutting tool
3. The rigidity of the cutting tool
4. Rigidity of work and machine
5. Power rating of the machine

Question 20

Differences between Roughing and Finishing?

Answer 20

In production, several roughing cuts are usually taken on the part, followed by one or two finishing cuts

Roughing
- removes large amounts of material from starting workpiece
-Creates a shape close to the desired geometry, but leaves some material for finish cutting.
-High feeds and depths, low speeds

Finishing
– completes part of geometry
-Final dimensions, tolerances, and finish
-Low feeds and depths, high cutting speeds

Question 21

Rough Cut :

1. ______ feed rate
2. ______ depth of cut
3. ______ chip load on cutter
4. ______ stock removal rate
5. ______ surface finish
6. ______ dimensional accuracy
7. ______ tolerance

Answer 21

Rough Cut :

1. [Higher] feed rate
2. [Higher] depth of cut
3. [Higher] chip load on cutter
4. [Higher] stock removal rate
5. [Poor] surface finish
6. [Poor] dimensional accuracy
7. [Poor] tolerance

Question 22

Finish Cut :

1. ______ feed rate
2. ______ depth of cut
3. ______ chip load on cutter
4. ______ stock removal rate
5. ______ surface finish
6. ______ dimensional accuracy
7. ______ tolerance

Answer 22

Finish Cut :

1. [Low] feed rate
2. [Low] depth of cut
3. [Lower] chip load on cutter
4. [Low] stock removal rate
5. [Good] surface finish
6. [High] dimensional accuracy
7. [Close] tolerance