Metalworking

Question 0

What two primary functions do cutting fluids perform?

Answer 0

Cooling

Lubrication

Question 1

Name three general classifications of fluids used in cutting and grinding.

Answer 1

Soluble oils (petroleum, semi-synthetic, full synthetic)
Neat oils
Tri-purpose oils
Mineral cutting oils
Chemical or synthetic coolants

Question 2

What is the most important characteristic of a soluble oil?

Answer 2

It must mix easily with water to form a stable emulsion.

Question 3

The primary function of a soluble oil emulsion in metalworking is as a ___________.

Answer 3

Coolant

Question 4

In order to form a stable emulsion of oil and water, which should be added to which?

Answer 4

Oil is added slowly to water (remember to put the water in the bathtub first before you get in!) OIL-IN-WATER

Question 5

Why does hard water make it difficult to form a stable emulsion?

Answer 5

Minerals (calcium & magnesium) in the water react with emulsifiers to form insoluble soaps.

Question 6

Water with a hardness of more than ______ ppm is considered hard.

Answer 6

300

Question 7

List best practices to prevent degradation and odors in oil soluble fluids.

Answer 7

Keep the fluid aerated and circulating.
Monitor the condition of the fluid and add biocide as necessary.
Make sure the reservoir and lines are clean and free of bacteria and fungus before adding new oil.
Remove tramp oil.
Keep the system clean and free of contamination.

Question 8

What is the primary problem encountered with bacteria growth in oil emulsions?

Answer 8

Odor.

Also rust, corrosion of oil way, filter plugging and dermatitis.

Question 9

What is skimming of metalworking fluids?

Answer 9

Removal of tramp oil from the top of a soluble oil by means of a belt or other mechanical skimmer.

Question 10

Name four advantages of tri-purpose cutting oils.

Answer 10

1) Reduce inventory by consolidating lubricants
2) Eliminates tramp oil in cutting oil
3) No possibility of mixing the cutting oil (coolant) and the lubricating oil and putting one into the wrong application
4) Eliminates cross contamination of oils
5) May be used on ferrous & non-ferrous metals
6) Eliminates cutting oil dilution & resultant decreased performance

Question 11

What material has been used as one of the most effective extreme pressure additives for heavy- duty cutting?

Answer 11

Active sulfur

Question 12

What is the primary effect on a work-piece of using fatty additives in cutting fluids?

Answer 12

Smoother finishes (fatty oils are active at lower temperatures than chlorine or sulfur)

Question 13

Most EDM (electrical discharge machining) processes are performed with the work-piece submerged in a light petroleum fluid called the ______ fluid.

Answer 13

EDM (electrical discharge machining)

The fluid has a very low viscosity and high dielectric strength.

Question 14

The ____________ is generally regarded as the primary machine tool and the “father” of all others.

Answer 14

Lathe

Question 15

What is a slushing oil?

Answer 15

A temporary rust preventive applied to steel in process.

Question 16

What is the difference between high speed quenching and marquenching?

Answer 16

In high speed quenching, hot metal is immersed into a low to moderate temperature bath (< 300°F) to control cooling and hardness of the metal.
Marquenching uses a higher temperature bath and a more viscous fluid.

Question 17

What are ways to stop a cutting coolant from misting?

Answer 17

Use a fluid with an anti-mist additive, change from high pressure, low volume flow of fluid to low pressure, high volume flow.

Question 18

The primary metalworking operations performed on a lathe are ______ ___ _______.

Answer 18

Turning and boring

Question 19

Name three other specific operations that can be performed on a lathe.

Answer 19

Threading Reaming
Facing Polishing
Drilling Knurling

Question 20

Single or multi-spindle fully automated machine tools intended for mass production are generically called ___________.

Answer 20

Automatics

Question 21

The machine tool capable of compound cutting motions and generally used to produce complex three dimensional shapes is the _______ ______.

Answer 21

Milling machine

Question 22

Name two basic types of cylindrical grinders?

Answer 22

Center type

Centerless type

Question 23

Center type grinding where the width of the grinding wheel is equal to the length of the cylindrical surface being ground is called ________grinding.

Answer 23

Plunge

Question 24

Parts such as long shafts, hollow wrist pins, etc. that can’t be ground on a center type grinder are normally ground on what type of grinder?

Answer 24

Centerless

Question 25

What is the primary difference between a shaper and a planer?

Answer 25

With a shaper the workpiece is clamped to a stationary table and the tool moves across. On a planer the tool is stationary and the workpiece moves past the tool.

Question 26

A __________is a cutting tool that is pushed or pulled past or through the workpiece to produce a machined surface that conforms to the shape of this tool.

Answer 26

Broach

Question 27

The relatively new machine tool that will, in one setup, perform several machining operations on several surfaces of a workpiece, including automatically selecting the proper tool from a storage magazine, is generally called a ________ ________.

Answer 27

Machining center

Question 28

Name at least eight machining operations that a machining center can perform?

Answer 28

Turning Milling Boring Drilling Threading Spotting Facing Knurling Counterboring Tapping

Question 29

Name four major benefits of machining centers?

Answer 29

Fewer machine tools needed in shop Faster production of parts Can produce parts with finer tolerances Fewer machine tool operators needed

Question 30

Name the five major types of lubricants used in and on machine tools?

Answer 30

``` Way lubricants Gear lubricants Hydraulic oils Greases Metalworking fluids / coolants ```

Question 31

The metal removal process by which EDM machines operate is called ___________ _________ ___________.

Answer 31

Electrostatic discharge machining

Question 32

In the EDM process, the tool anode is the _____________ and the cathode is the ______________.

Answer 32

Workpiece | Tool

Question 33

Name five desirable properties of dielectric fluids?

Answer 33

Reasonably high flash point for safety Low viscosity for fluidity and fast settling of fines Capacity for convective cooling Unobjectionable odor Allow passage of high peak discharge current when ruptured

Question 34

In machining what are the two fundamental physical processes?

Answer 34

Formation of the chip | Movement of the chip over the tool

Question 35

In machining, the tool cutting through the workpiece generates heat through what two sources?

Answer 35

From frictional resistance of the tool moving across the workpiece From deformation for metal

Question 36

Name four other functions that cutting fluids should perform?

Answer 36

Protect machines, tools and other parts from rust Must not discolor machined parts Should not produce smoke or mist Must not have disagreeable odor

Question 37

In some mild machining operations, especially with aluminum or other non-ferrous metals, low viscosity _________mineral oils may be used.

Answer 37

Straight

Question 38

For many severe heavy duty machining operations, a fluid with __________ __________ additives is required.

Answer 38

Extreme pressure

Question 39

List at least five additives commonly used in metal working fluids?

Answer 39

Antioxidant Metal deactivators Extreme pressure Tackiness agent Rust inhibitor Odor control agent Foam inhibitor Pour point depressant Emulsifier

Question 40

For many years, ________has been used as one of the most effective extreme pressure additives for heavy duty cutting oils.

Answer 40

Sulfur

Question 41

What is the primary advantage of transparent cutting oil?

Answer 41

Operator can see the tool and workpiece.

Question 42

Tri-Purpose cutting oils serve what three functions on automatic screw machines?

Answer 42

Cutting Fluid Machine tool lubricant Hydraulic fluid

Question 43

Soluble oils are not soluble, but many more appropriately be called __________ oils.

Answer 43

Emulsifiable

Question 44

What are two important characteristics of a soluble oil?

Answer 44

Emulsify easily | Form stable emulsion

Question 45

In an emulsion, the liquid which is broken up into globules is called the ________phase while the surrounding fluid is the __________phase.

Answer 45

Dispersed (internal) | Continuous (external)

Question 46

Soluble oil emulsions used for metalworking are normally what type? Give brief description.

Answer 46

Oil-in-water | The oil is the internal (dispersed) with the water being the continuous (external) phase.

Question 47

A soluble oil emulsion in which the water is dispersed and the oil is in the continuous phase is called an ________emulsion.

Answer 47

Invert

Question 48

Invert emulsions are sometimes used in what kind of application?

Answer 48

Fire resistant hydraulic fluids

Question 49

What kind of water condition makes it easier to form stable emulsions?

Answer 49

Soft water

Question 50

Describe the emulsion mixture (blend) for soluble oil emulsions used in grinding? Why is it used?

Answer 50

Lean | Provides better cooling & settling of chips and fines.

Question 51

Heavy duty soluble oils generally contain ________viscosity base oils.

Answer 51

Higher

Question 52

The key to preparing a stable soluble oil emulsion is in the proper _______.

Answer 52

Mixing

Question 53

Name the four steps in preparing a stable oil emulsion?

Answer 53

Use clean, soft water Use clean containers for mixing Water and oil should be approximately room temperature Add oil into water slowly and stir continuously

Question 54

What two minerals are normally found in appreciable amounts in hard water?

Answer 54

Calcium | Magnesium

Question 55

Describe the predominant characteristic of soluble oil emulsions and chemical coolants?

Answer 55

Coolant with little lubricity

Question 56

To improve lubricity the oil content of an emulsion should be _________ .

Answer 56

Increased

Question 57

In what type of operation are cutting oils containing EP additives more effective?

Answer 57

Slow speed with heavy cuts

Question 58

What is the primary result of using fatty oils in cutting fluids?

Answer 58

Improve surface finish

Question 59

What two primary actions should be taken to reduce built-up edge of cutting tools?

Answer 59

Use a cutting fluid with more sulfur &/or chlorine. | Increase cutting speed

Question 60

Carbide and ceramic cutting tools perform best at ______cutting speeds.

Answer 60

High

Question 61

What type of metalworking fluids are usually used with carbide and ceramic tools? Why?

Answer 61

Soluble oils or chemical coolants | Cooling is more important than lubricity

Question 62

What type of metalworking fluids should never be used on magnesium?

Answer 62

Those that contain water

Question 63

Name three primary characteristics that a good gun drilling / deep hole drilling / trepanning drilling fluid possess?

Answer 63

Low viscosity – cooling and chip removal Some EP for use on hard materials Fatty oil for good surface finish

Question 64

Explain why machine operators should be encouraged to NOT spit or pour old coffee into the soluble oil returns through?

Answer 64

Provides good culture medium for bacteria growth.

Question 65

What is the primary complaint encountered with bacteria growth in oil emulsions?

Answer 65

Obnoxious odor

Question 66

A built up edge on the cutting tool is caused by ______ __ _____ __ ___ ____ _____.

Answer 66

Welding of metal to the tool point

Question 67

Name three characteristics of a good way lubricant?

Answer 67

``` Good lubricity Tackiness to prevent squeeze out Prevent stick slip Rust protection Easy pumpability ```

Question 68

If you must dilute a soluble oil emulsion to make it leaner, should you add water to the emulsion? WHY?

Answer 68

NO | Properly mix leaner emulsion outside the machine and add slowly to the emulsion reservoir.

Question 69

In general, ______viscosity fluids are used with slower speed applications and _______viscosity fluids are used with higher speed applications.

Answer 69

Higher | Lower

Question 70

What is the most important prevention of dermatitis for machine operators?

Answer 70

Personal Hygiene | Cleanliness

Question 71

Can dermatitis be caused by the cutting fluid itself? Explain?

Answer 71

Yes | Some people may develop sensitivity to fluids and / or additives

Question 72

Besides the fluids themselves, name three other things which may cause dermatitis or skin irritations?

Answer 72

Metal shavings and fines in the fluid Bacteria in the fluid Contaminants in the fluid

Question 73

Which type of metalworking fluids are most susceptible to bacterial contamination? Explain?

Answer 73

Soluble / Emulsifiable oils | The bacteria / fungi live in the water phase and feed on hydrocarbons and contaminants in the absence of oxygen.

Question 74

Name the major types of lubricants used in and on machine tools.

Answer 74

``` Coolant Way lubricant Hydraulic oil Grease Spindle oil Gear oil ```

Question 75

What are some methods of controlling odor in soluble cutting fluids?

Answer 75

Keep the fluid aerated and circulating. Monitor the condition of the fluid and add biocide as necessary. Make sure the reservoir and lines are clean and free of bacteria and fungus before adding new oil. Remove tramp oil. Keep the system clean and free of contamination.

Question 76

What are three types of dermatitis? Contact, allergic, skin injury, chronic, acute

Answer 76

``` Contact Allergic Skin injury Chronic Acute ```

Question 77

Which metals are more likely to cause human skin disorders?

Answer 77

Nickel Chromium Cobalt

Question 78

What is BUE?

Answer 78

``` Built up edge Metal becomes attached to cutting tool just above the point of contact with the work piece. Reduce BUE (built up edge) with additional EP additives. ```

Question 79

What are the three things to look for in a water-soluble hydraulic fluid filter plugs.

Answer 79

Soap scum Fungus or mold Dirt and debris

Question 80

What three things would you monitor in an in-service water-soluble oil?

Answer 80

Microbial growth Water content PH

Question 81

What is a machinability rating?

Answer 81

Rating assigned to metals that indicates machining difficulty based on tool life, chip size, surface finish, power consumption.

Question 82

What is a refractometer?

Answer 82

Checks concentration of oil in soluble oils.

Question 83

What is tramp oil?

Answer 83

Machine oil such as hydraulic oil or way oil that ends up in the metal working fluid.

Question 84

Machine tool ways require oils with ________ additives.

Answer 84

Stick slip

Question 85

What is the G-ratio in relation to grinding applications?

Answer 85

The ratio of the volume of metal removed to the volume of grinding abrasive consumed.

Question 86

What types of additives are used in cutting oils to reduce heat from boundary lubrication?

Answer 86

EP additives such as sulfur and chlorine.