1
Q
How is accuracy and reliability maintained during the service life of measuring tools?
A
- tools must be handled with care, kept clean, and used only for their specific purposes
- apply a thin coat of oil to any moving part
2
Q
For best accuracy, how should the measuring tool be held in relation to the piece to be measured?
Figure 1
A
- the measuring instrument must be exactly in line with the axis of measurement
3
Q
What is the accuracy limitation of a measuring tool?
A
- the accuracy limitation is determined by its smallest scale graduation
4
Q
What are steel rules made of and what lengths are standard?
A
- made of hardened and tempered spring steel
- flexible, semi-flexible or ridged steel, graduates in metric or imperial, or both
- available in a variety of lengths: — 6” 150mm — 12” 300mm — 18” 450mm — 24” 600mm
5
Q
How long is 1mm in inches?
A
- 1mm = 0.03937”
- 1” = 25.4mm
6
Q
To what degree of accuracy are metric and imperial steel rules graduated?
A
- Metric — graduated in millimetres and half-millimetres
- Imperial — graduates in fractions or decimals of an inch - 1/8”, 1/16”, 1/32”, 1/64”
7
Q
Describe the construction and purposes of a vernier caliper.
A
- a precision measuring instrument which can be used to measure a wide range of sizes rapidly
- consists of a main frame (beam) and a moveable jaw
8
Q
Describe the operating principle of a vernier scale.
A
- a vernier caliper has a main scale on its beam and a vernier scale in the movable jaw
- the beam may be graduated in both of its sides or both of its edges
- May be used to measure inside and outside dimensions and depths
- May also be used as a layout instrument
9
Q
Describe how to read a metric vernier scale.
A
1 - read the whole number (3cm = 30mm)
2 - read the number of graduations the moveable jaw has passed (2mm)
3 - read along the vernier scale to find the increment which lines up to a graduation on the beam (0.66 mm)
4 - Add these figures together to achieve the total reading (30.00+2.00+0.66=32.66mm)
10
Q
Describe how to read imperial vernier scales in both 0.025” and 0.050” graduations
A
1- note the X” increment on the beam
2- note the 0.X” increment on the beam
3- note the 0.0XX increment on the vernier scale
4- Add together to get total reading
11
Q
What is the principle of the micrometer based upon?
A
- based on the pitch and lead of a thread
- at a specific pitch of a thread, the lead is a set distance
12
Q
List the parts of a micrometer.
A
- spindle — has a thread ground on its periphery and acts as a bolt
- thimble — has graduations around it and is attached to spindle
- sleeve — has an internal thread which acts as a nut in which the spindle and thimble assembly fit — also has a line along its axis which acts as a datum
- anvil — connected to the sleeve by means of the frame. Acts as a fixed position from which the spindle moves. This distance is calibrated by the graduations on the thimble to the datum line on the sleeve
- ratchet — the amount of torque applied to the thimble can be controlled and allow the user to maintain consistent readings regardless of feel
- lock nut — allows the the spindle to be locked to prevent movement after a measurement is taken
13
Q
Describe the operating principles of a metric micrometer.
A
- the spindle thread has a pitch of 0.5mm which equates to a lead of 0.5mm. In one rotation of the spindle, it moves 0.5mm
- the sleeve of the micrometer is graduated in 0.5mm increments
- the thimble of the micrometer is divided into 50 increments around its periphery. Every increment represents 1/100th of a millimeter (0.01mm). Every fifth increment is numbered for easy reading
14
Q
Describe how to read a metric micrometer.
A
- note the X mm reading on the sleeve
- note the upper or lower graduation on the sleeve
- note the graduation on the thimble in line with the datum
- Add together to get total reading
15
Q
Describe the operating principle of an imperial micrometer.
A
- the spindle thread has a 40 threads per inch (tpi) which equates to a lead of 0.025”. In one rotation of the spindle, it moves 0.025”
- the sleeve of the micrometer is graduated in 0.025” increments
- the thimble of the micrometer is divided into 25 increments around its periphery. Every increment represents 0.001”. Every increment on the thimble is numbered and every fifth increment is numbered for easy reading
16
Q
Describe how to read an imperial micrometer
A
- note the reading on the sleeve
- note the upper or lower graduation on the sleeve
- note the graduation on the thimble in line with the datum
- Add together to get total reading
17
Q
What accuracy can be achieved using a mobile cornered with a vernier scale?
A
- this vernier scale divides each 0.001” into 10 equal increments which provides reading accuracy of 0.0001”
18
Q
What are the applications for comparison measuring tools?
A
- used to measure or gauge variations or clearances
- have no capacity within themselves to show a measurement
- used to compare a size with a known measurement achieved from measuring tools
19
Q
What are the uses for dial indicators?
A
- used to measure movements such as the run out of a shaft or to compare parts against each other
- continuous reading dial indicator is used to measure run-out of shafts and other rotary parts
- the back plunger is used to align and set up parts of equipment
20
Q
What care should be taken to ensure accurate readings?
A
- take care to ensure that the axis of the indicator spindle is in line with the axis of measurement
21
Q
Describe how to take a clearance measurement with feeler gauges.
A
- feeler gauges have each leaf marked with a size
- if a number of leaves are stacked together, the thickness should be checked with a micrometer
22
Q
Describe how to duplicate shaft sizes and bores with outside and inside calipers.
A
- outside spring caliper
— the smallest size in which the caliper can pass over the shaft without resistance on its legs represents the size of the shaft - inside spring caliper
— the largest size in which the caliper can rock within the bore without resistance on its legs represents the size of the bore
23
Q
Describe how to duplicate the size of a bore with a telescope gauge.
A
- insert the gauge into the bore
- move the handle slightly off the axis of the bore
- release the lock nut to allow the plunger to contact the bore
- snug the lock nut
- arc the handle through the axis of the bore (only once)
- remove the gauge and measure with a measuring tool
24
Q
What are the purposes of layout tools?
A
- used to prepare the surface, and to scribe and mark lines, arcs, circles, angles and points
25
What substances are used to enable the millwright to see the layout lines more readily?
- layout dye or bluing is a blue dye which can be brushed or sprayed onto a surface to enable the layout lines to be seen more easily
- white latex paint or chalk can be used if dye not readily available
26
Describe the uses for the following:
| - scribers
- pencil-like tool used to mark layout lines on the surface of the workpiece
- single or double-ended
27
Describe the uses for the following:
| - straight edges
- used to lay out straight lines, and to check surfaces for flatness and alignment
28
Describe the uses for the following:
| - spring dividers and trammels
Spring dividers
— used to scribe arcs and circles and to transfer measurements
— useful in dividing lines, arcs and circles into equal distances
Trammel
— used in the same manner as a spring divider except that the beam allows the points to be spread a larger distance
29
Describe the uses for the following:
| - hermaphrodite calipers
- used to lay out lines parallel to an edge and to find the centre of round or irregular shaped objects
- by passing the bent leg past the point, they can also be used to scribe a line parallel to a flange
30
Describe the uses for all the main parts of a combination set.
- Steel rule
— allows for the attachment of the various heads
- Square head
— used to lay or lines or measure parts on 90 and 45 degrees, lay out and measure surfaces parallel to an edge, or act as a depth gauge
— also has a spirit level parallel to the square edge and a scribe fitted into it
- Protractor head
— used to lay out and measure angles (1 degree accuracy)
- Centre head - used to find the centre of round stock
31
Describe the uses for the following:
| - ball-peen hammer
- the peen end is used to shape metal
- the face end is used to strike without leaving an imprint
- also used to strike objects such as punches and pins
32
Describe the uses for the following:
| - prick punch
- used to accurately mark a line or centre of intersecting lines
- ground with a 30-60 degree point
33
Describe the uses for the following:
| - centre punch
- used to define centre marks for holes to be drilled
| - ground with a 90 degree point which makes a wider indentation for drilling
34
What care should be taken when using a striking tool?
- always use protective eye wear
- spark proof tools in hazardous environments
- don’t hammer you hands
35
Describe the procedure for sharpening a punch and removing the mushroomed head.
- do not allow the point to overheat (turn colour)
- the cut of the grinding wheel must be along the axis of the punch
- always grind off the mushroom from a used punch
36
What protective wear should always be used when grinding?
- protective eyewear
| - face shield
37
What are the purposes of honing stones?
- designed to remove small amounts of material from parts or tools
- remove birds
- putting an edge on tooling
- removes rough edges
38
How are honing stones constructed and what are the common abrasives?
- consist of an abrasive and a bond which holds the abrasives together
- commonly used abrasives
A — aluminum oxide
C — silicon carbide
D — diamond
39
How are honing stones lubricated?
- honing stones require a lubricant and can be manufactured to use either oil, solvent, or water. Be aware of which lubricant is used.
40
What are the purposes of the three common types of scrapers?
- flat scraper — used to remove height spots on flat surfaces
- triangular scraper — used to remove sharp edges off a part
- bearing scraper — used to scrape concave surfaces such as bronze and Babbitt bearings
41
Describe how to scrape mating records and record the results.
- apply a thin film of bluing to the reference surface
- rub the reference surface onto the work. The high spots are marked by the transfer of bluing from the reference surface onto the work
- scrape these blue marks off
- repeat this procedure
- when the work shows a uniform coverage (80%). The scraping is complete
- to record the quality of the scraping, use a thin sheet of paper. After the scraping is complete and before the bluing is wiped, place the paper onto the scraped surface and he place the mating surface onto it. This transfers the blue into the paper and creates the record of the job
42
Describe how to sharpen a scraper
- allow the curvature of the grinding wheel to create a slight hollow along the edge of the scraper
- then when the edge is honed, the stone contacts on the cutting edge of the scraper
43
Describe the construction of a file
- common shapes -- flat (mill), square, triangular (three-square), half-round, and round
- the size of a file is determined by the length from the heel to the point
- common sizes -- 6", 8", and 10"
- coarseness -- single-cut, double-cut, bastard-cut, second-cut, smooth-cut
- to ensure an effective cutting surface, files are made hard and, therefore, brittle
44
Describe the procedure for filing
- have a balanced stance
- ensure that the part is held securely
- keep the file clean in order to produce a smooth surface
- apply a light pressure on the forward stroke only. If heavy pressure is applied, the teeth of the file will become clogged and scratch the surface of the part. This is called "pinning". Pinning can be reduced by applying chalk to the surface of the file.
- if pinning begins, remove the pins between the teeth before continuing. Do this b rubbing a file card or a piece of brass, copper or wood, through the teeth.
- use the full length of the file if possible
45
Describe draw filing
- produces a flat, smooth surface
- place the file square to the work and to the direction of movement
- hold the file on both ends with your index fingers applying pressure to the file directly above the work.
- draw the file toward you
46
What are cold chisels made of and what are the uses for the four common chisels?
- made of hardened and tempered, high-carbon steel
- flat cold chisels -- chip or cut metal, cutting thin plate, shearing off rivet or bolt heads, removing weld spots, dismantling corroded and seized components
- cape chisels -- cut narrow, square-bottomed grooves (keyways)
- round nose chisels -- cut round bottom grooves (oil grooves)
- diamond point chisels -- finish off square corners and create square- or diamond-shaped grooves
47
How are chisels maintained to ensure safe and efficient use?
- keep the cutting edge of the chisel sharp. A dull chisel can deflect away from the workpiece instead of biting in. This can cause the chisel to fly out of the hand of the worker and cause injuries
- constant hammering on the head of a chisel causes it to flare outwards (mushroom
48
Describe the construction of a hand hacksaw and the blades
- consist of a frame, a handle, a blade, and a blade tensioning device
- the handle of the hacksaw is meant to protect the hand from injury if the hacksaw slips or the blade breaks
- the frames are either fixed or adjustable
- - fixed frames - accommodate one length of blade only. generally more rigid than adjustable
- - adjustable frames - accommodate a variety of blade lengths
- most common blade orientations - 0, 45, 90
Hacksaw blades -- commonly available in 250mm (10") and 300mm (12") and types such as rigid and flexible
All-hard blades -- fully hardened, high-speed steel. cut tough materials. blades brittle and break easily
Flexible blades - carbon or bi metal. cut materials ranging from tough to soft. blades flex without breaking
49
Why is a new hacksaw blade never started in the kerf of the old blade?
- the new blade must not be placed in the original cut because of the narrower kerf will cause the teeth to wear prematurely
- start a new cut in a new location, either on the other side of the workpiece or in the waste section beside the existing cut
50
How is the correct blade selected for the job?
- the pitch of the teeth is used when selecting the correct blade for the job
- thick materials - a coarse blade should be used to allow for plenty of chip clearance
- thin materials - a fine pitch blade should be used to prevent the teeth from taking too heavy a chip lead, causing tooth breakage
- rule of thumb -- at least 2 teeth (3) must be in contact with the material at all times
51
Describe how to use a hacksaw and make a cut
PREPARE THE SAW AND WORKPIECE
- choose the correct blade for the job
- ensure that the blade is mounted with its teeth pointing away from the handle
- adjust the tension so that the blade cannot flex or bend
- secure the workpiece and, if necessary, support it.
MAKE THE CUT
- grip the hacksaw handle firmly, and be sure-footed and comfortable
- position the blade on the workpiece on the preferred side of the layout mark
- begin to cut with sufficient down-pressure, to keep the teeth cutting, on the forward stroke only
- make long, steady strokes using the full length of the blade, to maximize the life of the blade
- maintain a cutting speed of 40 to 60 strokes per minute
- when the cut is completed, store the hacksaw in such a manner so that the teeth are protected from damage
52
What materials are power cutting tools made of?
- carbon steel
- high-speed steel (HSS)
- cobalt HSS (used more often in industry)
- carbide
- ceramic
- diamond
53
Describe the construction of a twist drill.
- carbide twist drills -- made of an alloy steel body with cemented carbide cutting edges
- HSS and cobalt HSS twist drills -- body made of solid HSS and their shanks made of a softer material
- the body of a standard twist drill consists of
- - a point - two cutting edges, heels, margins, lip clearances, and chisel edge
- - helical flutes
- - lands
- - straight or tapered (morse) shanks
54
What point angles are recommended for different materials?
- 118 degrees -- general purpose drilling of materials such as mild steel (or similar hardness)
- 150 degrees -- hard materials such as heat-treated allow steel
- 90 degrees - soft materials such as aluminium or thin materials
55
What is the correct lip clearance for twist drills?
- the lip clearance behind the cutting edge should range from 8-12 degrees
- when the correct lip clearance is achieved, the chisel edge angle (angle between chisel edge and cutting edge) will be about 135 degrees
56
Describe the procedure for sharpening a twist drill.
- begin by holding the drill horizontally with the drill's axis slightly above the axis of the grinder
- align the plane of the drill's cutting edge parallel to the axis of the grinder and at 59* degrees from the face of the grinding wheel
- touch the wheel with the drill and sweep it upwards along the wheel (do not rotate the drill)
- repeat a few times then switch to the other cutting edge and repeat procedure
- when both cutting edges are ground the same amount, check angle and length of the cutting edge with a drill point gauge
- when the length of both cutting edges are the same and the drill pint angle and the lip clearances are correct the drill should be ready to use
57
Describe brassing off a drill.
- when using a twist drill to cut brass, bronze, plastic, and other materials which are soft and relatively brittle, the cutting edge must be flattened
- flattening the cutting edge prevents the drill from biting into the material too rapidly and overloading the drill
58
Describe the construction of solid parallel reamers.
-- Machine reamers
- designed to be used in equipment such as a drill press, engine lathe or milling machine
- the shank is either straight, for chucking, or has a morse taper
-
59
Describe the procedure for drilling and reaming a hole.
- ensure that the drilled hole is located accurately before reaming
- holes to be reamed must be drilled undersize to allow the reamer to cut it to size
- the amount of material left for reaming depend on the type of reamer to be used
60
What is the effect on a reamer if it is rotated backwards?
- never rotate the reamer backwards because it will dull the reamer
61
Describe the construction and purpose of adjustable reamers.
- primarily made as hand reamers
- consist of a set of blades set into grooves with a tapered base
- nuts on either end of the blades adjust the blades along the body. this allows the reamer's size to be changed to the desired amount
62
Describe the procedure for reaming tapered holes
- when preparing holes for reaming, step-drill them to remove excess material
- ensure that enough material is left in the hole, at the bottom of the steps, for the reamer to clean up
63
Describe the various types of end mills.
- two-flute end mills
- - generally made with one end cutting edge slightly longer then the other. This allows it to centre-cut and plunge into the workpiece like a drill.
- - this type of end mill often called slot drills
- four-flute end mills
- - normally have a centre hole drilled in the cutting end of the tool. This allows for easier sharpening but will not allow it to plunger into the workpiece.
- - this type of end mill must enter the work piece from the end
- centre cutting four-flute end mill
- - have the strength of a four-flute cutter with the end cutting capabilities of a slot drill
64
Define cutting speed.
- the speed with which the saw teeth and cut object move past each other
- sometimes called the surface speed of the operation
- the control of the cutting speed is vital to the life of the cutter
- cutting speed (CS) is expressed in metres per minute (m/min) or feet per minute (ft/min). Each material has a recommended CS for each type of cutter.
65
How does the cutting speed of carbide cutters and machine reamers compare to HSS cutters?
- the CS for carbide cutters is approximately 2.5 times faster than for HSS cutters
- the CS for machine reaming is half that of HSS
66
What steps should be taken to ensure quality work and maximum cutter life?
- to ensure maximum life fo the cutter, use adequate coolant and the correct rpm
- failure to supply adequate coolant and the correct speed results in premature tool wear, breakage and/or metallurgical damage to the workpiece
67
Calculate the rpm of an 8mm drill used to cut plain carbon steel.
Use lowest recommended speed
rpm
= (CS X 1000) / (Pi X D)
= (CS X 320) / D
68
Describe the construction of a drill press.
-
69
Describe the various types of portable drills.
-
70
What safety precautions should be observed when using drill presses or portable drills?
-
71
Describe the construction and purpose of portable magnetic drill presses.
-
72
What additional safety precautions must be observed while using magnetic base drills?
-
73
Describe a portable key seat cutter.
-
74
Describe the operating principle of powder-actuated tools
-
75
How are powder-actuated tools regulated to ensure workers safety?
-
Millwright Manual
flashcards
Decks in class (24)
# Cards
-
Chapter 15 - Pumps112
-
Chapter 14 - Seals74
-
Chapter 17 - Pneumatic Systems78
-
Chapter 18 - Prime Movers118
-
Chapter 19 - Material Handling Systems159
-
Chapter 20 - Preventative Maintenance66
-
Chapter 21 - Ventilation And Pollution Control34
-
Chapter 22 - Installation And Levelling85
-
Chapter 23 - Alignment78
-
Chapter 12 - Gear Drives75
-
Chapter 4 - Shop Practices75
-
Chapter 13 - Couplings And Clutches64
-
Chapter 5 - Fastener And Threads93
-
Chapter 6 - Lubrication56
-
Chapter 7 - Rigging And Lifting95
-
Chapter 8 - Shafts And Attachments84
-
Chapter 9 - Bearings102
-
Chapter 10 - Belt Drives64
-
Chapter 11 - Chain Drives43
-
Chapter 16 - Hydraulic Systems159
-
Chapter 1 - Safety40
-
Chapter 2 - Trade Science116
-
Chapter 3 - Technical Drawings74
-
RSOS Procedures0
