Machine Tool Practices, 11e (Kibbe)
Section F – Preparation for Machining Operations
1) Positive tool rake works best for cutting:
A) Brass and bronze
B) Tough, strong metals
C) Hard brittle materials
D) Soft, gummy metals
2) When using low cutting speeds and negative rake tools to cut soft metals, the result is often:
A) A long, uniform chip
B) A built-up edge
C) The metal splitting ahead of the tool
D) A good finish
3) In what ways does a cutting tool remove metal?
A) It produces extreme heat at the tip of the tool thus melting the chip/parent metal/interface
B) Through the process of abrasion
C) By splitting the metal just ahead of the tool
D) By causing it to slide ahead of the tool on a shear plane
4) When a soft metal produces thick, segmented chips while being turned on a lathe and no
cutting fluid is used, what kind of surface finish is expected?
A) Smooth and shiny
B) One having very coarse tool marks
C) Burnished smooth
D) A torn, disrupted, rough finish
5) Negative rake tools require:
A) More frequent resharpening
B) Less horsepower for a given cut
C) Less frequent resharpening
D) More horsepower for a given cut
6) Negative-rake tools produce poor finishes at low cutting speeds but give a good finish at high
speeds.
7) Why would 400 SPFM be better that 100 SFPM when using carbide cutting tools?
A) Less heat is produced at 400 SFPM than at 100 SFPM
B) There would be better shaped chipsIt is not better
C) The higher speed would provide a better finish
D) It depends on the machine being usedThe higher speed is less likely to burn the edge of a
cutting tool
8) If a machined part has an irregular, torn surface with many micro cracks due to poor practice,
what can happen to the service life of this part?
A) It may be extended
B) It could cause corrosion
C) There would be no appreciable effect
D) The part could fail early due to metal fatigue
9) How would you rate the general machinability of a very hard metal?
A) Medium
B) No rating because hardness has no effect on machinability.
C) Low
D) High
10) Which chip formation would be best for lathe machining?
A) Long, wiry strands
B) 9-shaped
C) Segmented
D) Spiral
11) Relative difficulty of machining with regard to tool life, surface finish and power
consumption is called:
A) Hardenability
B) Machinability
C) Surface finish rating
D) Metal removal index rating
12) Using RPM=4CS/D, how fast should a 1/2 in. drill turn when drilling mild steel in a drill
press if CS is 90 SFPM?
A) 360 RPM
B) 90 RPM
C) 180 RPM
D) 720 RPM
13) If the 1/2 drill in question 1 was held in the tailstock of the lathe instead of a drill press, how
fast should the lathe spindle turn?
A) 180 RPM
B) 2880 RPM
C) 720 RPM
D) 360 RPM
14) Blue chips are acceptable and in fact desirable when using carbides.
15) The cutting speed for carbide tools is normally three to four times higher than high-speed
cutting tools.
16) Suppose in the previous question that athe lathe or drill press could not be set at the exact
calculated speed. What would you do?
A) If it starts smoking and burning the tool, set it lower
B) Just ignore speeds and set where it sounds about right
C) Set to the next lower speed
D) Set to the next higher speed
17) A 4.000 in. dia. shaft of alloy steel, with a cutting speed of 50 SFPM, is turned in a lathe
using a high-speed tool. At what RPM should the machine be set?
A) 400
B) 200
C) 50
D) 100
18) If a 6 in. dia. grinding wheel is turning at 3500 RPM, what is its cutting speed in SFPM?
A) 5250 or 5497 (depends on the value of pi in the calculation)
B) 1750
C) 21,000
D) 2333
19) How are feeds determined on a drill press?
A) IPR
B) RPM
C) IPM
D) SFPM
20) Roughing feeds in IPR on a small (12 in. swing) lathe should not exceed:
A) .005
B) .100
C) .015 – .020
D) .200
1821) Table feeds in IPM are found on what type of machine?
A) Drill presses
B) Grinders
C) Lathes
D) Milling machines
22) The crossfeed setover amount on a surface grinder for roughing should be about:
A) 1/3 the width of the wheel face
B) 20 IPR
C) 1/4 in. per stroke
D) 20 IPM
1923) If IPM = feed per tooth × number of teeth on a cutter × RPM, what is the table feed in
inches per minute for a 10 tooth cutter turning at 50 RPM with a feed per tooth rate of .006 in.?
A) 3 IPM
B) 3000 IPM
C) 300 IPM
D) 30 IPM
204) What are the basic functions of a cutting fluid?
A) Cooling and lubrication
B) Cleaning and lubrication
C) Facilitating chip removal and lubrication
D) Cooling and flushing chips from the cutting tool
215) Three major types of cutting fluids (liquids) are:
A) Emulsion, synthetic and cutting oils
B) Semi-synthetic, emulsions, tram oils
C) Lubricating oils, soluble oils and transparent emulsions
D) Water, oil and emulsion
226) When a cutting fluid becomes rancid and has a bad odor, what should be done?
A) Avoid contact with rancid fluid when using the machine
B) Chemicals should be added to cover up the odor
C) The operator should wear a respirator
D) The old fluid should be replaced and the tank cleaned
237) When an operator mixes cutting oils with water soluble coolant on a machine, what is often
the result?
A) A scum forms on the top of the coolant in the tank and it becomes rancid
B) The coolant pump stops working
C) The soluble oil becomes a richer mixture
D) The extra oil helps to protect the operator’s skin
248) Why do some synthetic cutting fluids irritate the skin when in prolonged contact?
A) It contains irritating chemicals
B) These fluids are acid based
C) It tends to remove the natural skin oils
D) These fluids are alkali based
259) If a machine such as a small drill press has no coolant pump, how do you best apply cutting
fluid the workpiece?
A) It should not be applied because the machine was not set up for cutting fluid
B) Pour it out of an oil can
C) Use and atomizer spray can
D) Use a pump oiler
2630) Sulfo-chlorinated cutting oils are better than water– based coolants for:
A) Grinding operations
B) Milling machine operations
C) High speed turning on the lathe
D) High pressure cutting such as tapping
2731) The most common method of applying cutting fluid on the machine is:
A) By flooding the workpiece area
B) With a brush
C) With a pump oil can
D) With a high– pressure jet
2832) A single round nozzle supplying cutting fluid to a grinding wheel is rather inefficient
because:
A) A round coolant jet hits in only one place
B) The spinning wheel tends to blow it away
C) This is not a true statement
D) It floods the workpiece/tool area
2933) What is the greatest disadvantage of spray-mist systems?
A) They require a return hose and tank
B) They are messy
C) They spray the whole machine instead of the work/tool area
D) They do not lubricate the tool and work area very well
304) What materials are used to make straight carbide inserts?
A) Tantalum carbide, tungsten carbide, titanium carbide and cobalt
B) Tungsten, cobalt and titanium
C) Titanium carbide and cobalt
D) Cobalt and tungsten carbide
315) Normal wear is seen on a carbide tool as:
A) Cratering
B) Edge or flank wear
C) Breakdown due to built up edge
D) Breakage through thermal shock
326) Which insert shape is the strongest and offers the greatest number of possible cutting
edges?
A) Diamond
B) Round
C) Triangular
D) Square
337) Increasing the SFPM by 50 percent over cutting speeds recommended for carbides will:
A) Have no appreciable effect on carbide tool life
B) Have less effect on the tool life than increasing the recommended rate of feed by 50 percent
C) Decrease tool life by over 60 percent
D) Decrease tool life by over 80 percent
348) The selection of nose radius must be based upon:
A) The thickness of the insert, feed rate and depth of cut
B) Surface finish requirements as determined by part specifications and feed rate
C) Tool strength requirements as determined by feed rate and depth of cut
D) Tool strength and surface finish requirements
359) A style A tool set at 90 degrees to the axis of the work with a .030 inch feed will produce a
chip thickness of ________ in.
A) .003
B) .060
C) .015
D) .030
3640) The term “clearance” refers to:
A) Tool shank clearance below the carbide tip
B) End relief on the carbide part of a brazed tool
C) Side relief on a positive rake tool
D) Side relief on negative rake tools
3741) Ceramic tools are made of:
A) Aluminum and carbon
B) Cemented iron oxide
C) Porcelain
D) Aluminum oxide
3842) Ceramic tools should be used:
A) When excessive wear is evident on carbides
B) For low speeds only
C) On any lathe setup
D) For interrupted cutting
3943) Diamond and polycrystalline diamond tools are used to:
A) Make intermittent cuts at low speed
B) Replace carbide tools on most materials
C) Machine hard, abrasive materials at high speed
D) Take heavy cuts for high stock removal
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40) Carbide tools come in a variety of grades. Grade is based on the carbide’s wear resistance
and toughness. 44) Brazed carbide tools are ground on:
41) Which insert shape is the strongest?
A) Triangular
B) Diamond
C) Trigon
D) Round
42) Increasing the lead angle will reduce tool breakage.
43) Negative rake requires higher horsepower than neutral rake.
44) A CNMG432 insert would have an inscribed circle of
A) .125 inch
B) 4 mm.
C) .5 inch
D) .432 inch
45) A CNMG432 insert would have a thickness of
A) .125 inch
B) 4 mm.
C) ¼ inch
D) 3/16th inch
46) A CNMG432 insert would have a corner radius of
A) 2mm
B) 4 mm.
C) 1/32nd inch
D) 1/16th inch
A) Titanium oxide wheels
B) Tungsten carbide wheels
C) Aluminum oxide wheels
D) Silicon carbide wheels