Machine Tool Practices, 11e (Kibbe)
Section L – Grinding and Abrasive Machining Processes
1) Which of the following is not a type of grinder?
A) Vertical spindle with rotary table
B) All are common types of grinders
C) Horizontal spindle with reciprocating table
D) Horizontal spindle with rotary table
2) A universal cylindrical grinder can grind angular surfaces.
3) A centerless grinder is a cylindrical grinder without centers. They only have chucks or collets
for part holding.
4) Cylindrical grinders are typically used to sharpen tooling.
5) A surface grinder can typically produce a surface flat within plus or minus .0001.
6) For grinding steels, the most widely used abrasive is:
A) Silicon carbide
B) Aluminum oxide
C) Cubic boron nitride
D) Diamond
7) Which of the following grinding wheel shapes permits grinding on both the face and the wall
of the grinding wheel?
A) Type 1 – Straight wheel
B) Type 2 – Cylinder wheel
C) Type 6 – Straight cup wheel
D) Type 11 – Flaring cup wheel
8) The finest grit size of the ranges listed below is:
A) 8 to 46
B) 36 to 100
C) 150 to 240
D) Resinoid
9) In relation to the area of grinding contact, the grade of the wheel is the:
A) Strength with which the bond holds the grain
B) Relative hardness of the bond in the wheel
C) Relative hardness of the abrasive grain in the wheel
D) Duality standard of the abrasive grain
10) When a grinding wheel becomes loaded with bits of workpiece material, this shows that the
wheel:
A) Structure is too dense and/or the abrasive is too fine
B) Grit size is too coarse
C) Has the wrong abrasive
D) Grade is too soft
11) The bond in most machine shop grinding wheels is:
A) Shellac
B) Rubber
C) Resinoid
D) Vitrified
12) Microcrystalline cubic boron nitride would be particularly suited to which of the following
grinding applications?
A) Ferritic and martensitic stainless steels
B) Form grinding
C) Austenitic stainless steels
D) Cemented carbide grinding
13) In relation to the area of grinding contact, the grade of the wheel:
A) Remains about the same regardless of change
B) Should be harder as the contact area decreases
C) Should be hardest for grinding large flat surfaces
D) Should be harder as the contact area increases
14) Grinding on the periphery of an abrasive wheel:
A) Requires a somewhat softer wheel than for side grinding
B) Requires a harder wheel than for side grinding
C) Requires a definitely softer wheel than for side grinding
D) Has no effect on wheel grade
15) When a grinding wheel face becomes shiny and smooth or glazed, this shows that the wheel:
A) Grade is too hard
B) Grit size is too coarse
C) Structure is open
D) Has the wrong abrasive
16) Grinding wheel truing is:
A) Used mainly for form grinding preparation
B) The removal of workpiece material from the grinding wheel
C) The method of obtaining grinding wheel concentricity to the spindle
D) The removal of dulled abrasive grains
17) Grinding wheel dressing is done to:
A) Prevent slippage between the wheel and spindle
B) Prepare the wheel for form grinding
C) Make the grinding wheel concentric to the spindle
D) Sharpen the grinding wheel
18) On a grinding wheel rotating clockwise, the correct position for the single point diamond in a
dresser is:
A) At a 15 degree angle directly on the vertical center line
B) Vertical and directly on the center line
C) Pointed in the direction of rotation 15 degrees ahead of the center line
D) Pointing in the direction of rotation 15 degrees past the center line
19) In dressing a wheel for rough cuts, you should use:
A) Heavier cuts and fast traverse
B) Lighter cuts and fast traverse
C) Lighter passes (about .0005 in.) and slow traverse
D) Heavier cuts (about .001 in.) and slow traverse
20) The most common work-holding device for the surface grinder is the precision grinding vise.
21) There are two types of magnetic vises.
22) Spring-type clamps are used with vises to hold fragile parts for grinding.
23) Double-sided tape can be used to hold parts on a surface grinder.
24) Thin pieces can be distorted by the magnetic chuck during grinding.
25) Temperatures up to 2000°F are common at the point where the grain is cutting.
26) The wheel head assembly:
A) Is mounted to the grinding saddle
B) Has a fixed relationship to the table
C) Usually contains the spindle, bearings and the drive motor
D) All of the above
27) What is the most commonly used work holding device on the surface grinder?
A) Mechanical clamping of the work
B) The electromagnetic chuck
C) The electro-permanent chuck
D) The permanent magnetic chuck
28) The most precise handwheel control on the grinder is the:
A) Traverse
B) Down feed
C) Chuck
D) Cross feed
29) What two advantages does the electro-permanent chuck have over an electro-magnetic
chuck? (choose two)
A) It retains holding power if an electrical power failure occurs
B) It is less subject to corrosion
C) It generates more heat than the electromagnetic chuck
D) It generates less heat than the electromagnetic chuck
30) The importance of horizontal spindle surface grinding is increasing for what primary reason?
A) More machinists are capable of doing precision surface grinding
B) Horizontal grinding machines are getting less expensive
C) Tolerances of 50 millionths of an inch are common place today
D) All of the above
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312) As compared with grinding an unhardened workpiece of the same material, what change in
the selection of the grinding wheel would be desireable for grinding the workpiece in a hardened
condition?
A) A different type of abrasive is indicated, such as silicon carbide instead of aluminum oxide
B) The grinding wheel selection should be one grade softer
C) No change in wheel bonding is desired
D) The grinding wheel selection should be one grade harder
323) What variation ins cross feeding is usually applied for grinding harder workpieces of the
same material?
A) The cross feeding rate is increased
B) Cross feeding is usually changed from automatic to manual
C) The cross feeding rate is usually unchanged for differing hardness
D) The cross feeding rate is decreased
334) If “grinding in” or truing the grinder chuck becomes necessary, how do you determine when
the surface has been trued?
A) Apply pencil lines to the chuck and grind until they disappear
B) Grind and then indicate
C) You just uniformly take .001 in. off the surface
D) Don’t grind the chuck, use shims instead
35) To avoid the use of paper to protect the surface of the chuck, what must be done to prepare a
scaly heat-treated workpiece before grinding?
A) The workpiece must be annealed
B) Remove the chuck and clamp directly to the table
C) The workpiece must be tempered
D) The heat treatment scale must be removed before chucking
346) When at precaution should be observed in determining whether or not to use grinding fluid
while dressing a grinding wheel you should:?
A) Slow the RPMIf you grind wet, dress wet
B) Use a carbide dresserThe issue is not important. Diamonds don’t easily crack from thermal
stress
C) Not use coolantIf you grind dry, dress dry
D) Be sure that the coolant is reaching and flooding the diamond dresser
357) When grinding the “Vv” in ayour Vv- block, what critical caution should you observe?
A) You should not make contact with the side of the grinding wheel
B) You should shape the grinding wheel to form the v
C) You should be cautious in grinding with the side of the grinding wheel
D) No special caution is needed
38) How much material should be left for the finish grind on each surface of the v block?
A) .0005 inch
B) .015 inch
C) .003 to .005 inch
D) .010 inch
369) To square the end of a workpiece with a ground side, the surface clamped to the angle plate
must be:
A) The ground– side
B) The side opposite the ground side
C) The opposite end
D) Either of the other two sides
3740) Among cylindrical grinding machines, the greatest variety of work can be done on a:
A) Traverse grinder
B) Angle head grinder
C) Universal grinder
D) Plunge grinder
3841) The work center on the headstock:
A) Is always dead
B) May be live or dead, depending on the work type
C) Is always live
D) Drives the workpiece
3942) What is the purpose of the footstock spring-loaded spindle?
A) It facilitates installation and removal of the part in the cylindrical grinder
B) It keeps the lubricant in place
C) It maintains a constant pressure on the workpiece centers
D) Both A and B above
403) The work center in the footstock:
A) May be live or dead, depending on the work type
B) Drives the workpiece
C) Is always live
D) Is always a dead center
414) Can the plain cylindrical grinder produce a tapered (conical) surface?
A) No, it can only produce a true cylinder
B) No, the cylindrical grinder is for making precision bores
C) Yes, the table can be swiveled for this purpose
D) No, the machine was not designed for this purpose
425) On a cylindrical grinder, the workpiece surface moves in relation to the direction of travel
of the grinding wheel surface:
A) In the opposite direction
B) In the same direction
C) Alternately, in the same and opposite direction
D) In a direction determined by the machine design
436) Traverse grinding on a cylindrical grinder is most often done by:
A) Angling the wheel head to 45 degrees
B) Moving the rotating wheel back and forth along the workpiece
C) Moving the rotating workpiece back and forth across the face of the wheel
D) Swiveling the table to the desired angle
447) In cylindrical form grinding:
A) The grinding wheel is shaped to the desired geometry of the part
B) The operation is a type of plunge grinding
C) Both A and B above
D) The process Is a version of centerless grinding
458) Which of the following types of grinding cannot be done on a universal cylindrical grinder?
A) Rotary surface grinding
B) Traverse grinding
C) Reciprocating surface grinding
D) Internal grinding
469) Plunge grinding:
A) Is a type of internal grinding
B) Is a type of traverse grinding
C) Is cylindrical grinding without traversing
D) Is none of the above
4750) Very long tapered workpieces (over 3.000 inches) can be accomplished on the cylindrical
grinder by:
A) Offsetting the footstock
B) Using a form grinding wheel
C) Swiveling the table
D) Swiveling the wheel head
4851) If a part has a taper of .010 in./ft., the difference between two dial indicator readings 12
inches apart would be:
A) .1125 in.
B) .001 in.
C) .101 in.
D) .005 in.
4952) In center-type cylindrical grinding, done on dead centers:
A) The headstock end of the workpiece must always be lubricated
B) Both ends of the workpiece must always be lubricated
C) Sometimes neither end needs to be lubricated
D) The footstock end of the workpiece must always be lubricated
503) In adjusting a workpiece mounted on dead centers:
A) The footstock should remain unlocked to allow for expansion
B) The workpiece should have no axial play, but be free to rotate
C) The center adjustment should be tight enough to drive the part
D) None of the above
514) Set the table stops to have an overrun at each end of the workpiece. The amount of overrun
where possible is:
A) One-third of the wheel width
B) Two-thirds of the wheel width
C) One-half of the wheel width
D) At least an inch
525) Wheel speed in center-type cylindrical grinding is in the range of 5500 to 6500 SFPM.
Work speeds, for most part will probably be in the range of ________ SFPM.
A) 10 to 50
B) 50 to 100
C) 100 to 150
D) 150 to 200
536) In the final finish grinding on a hardened workpiece, the traverse rate should be reduced to
about how much of a grinding wheel width per workpiece revolution?
A) One-half
B) One-eighth
C) One-fourth
D) Three-fourths
547) For final finishing passes on the cylindrical grinder, the amount to be removed per traverse
should be:
A) .002 inch or less
B) .002 inch
C) .001 inch
D) .0002 in.
558) Air pressure is used in an air bearing fixture to:
A) Keep grinding dust and contaminants out of the bearing area between the spindle and bore of
the spindle housing
B) A and C are correct
C) Lock the fixture at the correct angle
D) Act as the bearing between the spindle and the bore of the spindle housing
569) End mills can be ground by using an air bearing fixture on a tool and cutter grinder.
5760) End mills are sharpened on a machine called a mill grinder.
5861) End mills cut on their primary clearance.
5962) The surface immediately behind the cutting edge is called the land.
603) When a milling cutter is sharpened, the primary clearance is ground first.
614) The correct land width will vary depending on the diameter of the cutter.
625) The indicator drop method is one method to measure cutter clearance. This method uses a
dial test indicator to measure the difference in height across the width of the land.
636) Secondary clearance is only required on large cutters.
647) The cutter clearance gage can measure clearance angles in degrees.
658) Grinding wheels used for tool and cutter grinding should be biased toward a friable,
medium-soft grade of about 60 grit.
669) A center height gage that is adjusted to the arbor centerline is used to set the toothrest blade
and the grinder spindle to the arbor centerline height.
6770) When sharpening slitting saws, the toothrest is mounted on the swivel table, because it is
necessary to hold the cutter in a fixed position to grind each tooth.
6871) If cutter primary clearances are excessive, the cutting edge may have a tendency to chip
due to cutting forces.
6972) The tool and cutter grinder is much more versatile for grinding cutters than other types of
universal grinders.
703) Clearance angles are different depending on the material to be machined with the cutter.
714) The tooth rest is attached to the wheel head when helical cutters are sharpened so that the
cutter tooth can be constantly kept in contact with the tooth rest blade as the cutter rotates
through its helix.
75) When grinding cutters, the second trial cut should be made 180 degrees from the first grind.