Millwright Mechanics Level 2 – Bearings Prep Exams
2025
1. What are the principle parts of a friction bearing housing?: Base, Base bolt
slots, cap and cap bolt holes.
2. What are friction bearing housings made from adn what factors influence
the choice of housing?: Cast Iron, Cast Steel, Fabricated Steel.
Choice depends on the Load, The Rotational Speed, the Direction of Pull and the
Support Design
3. How are friction bearing dimensions expressed?: In a fraction of their nominal
size.
4. Do all new bearings of the same shaft size have the same base-to-eye
measurement?: If they are from the same manufacturer.
5. What factors influence the choice of bearings?: Load, Rotational Speed,
Direction of the Pull and support Design
6. What are the applications for the following bearings?
a) Solid Bearings
b) Split bearings
c) Angle bearings
d) Integrated Bearings: a) Where Speed and Load are low. Where load is applied
on the top part of the bearing.
b) Where load is applied on the bottom portion of the bearing. Different bolt numbers
for loads.
c) When load is applied parallel to, or at a slight angle to, the horizontal. Or when the
bearing is mounted on the vertical support
d) Where the bearings are an integral part of the machine.
7. How does friction bearing joint design affect its integrity?: Position of the top
half may affect the bearing tolerances and load positions.
8. What qualities should a good bearing material have? (5 points): Softer than
the shaft material, low coefficient of friction, wear-resistant, a good heat conductor
and remain relatively stable with heat changes, readily available.
9. List Metals generally used in bearing liners and their applications. (5 points)-
: Babbitt - for general use
Brass (copper zinc alloy) - for higher speeds and heavier load than babbit
Bronze (coper tin alloy) - for higher speeds and heavier loading than babbitt
Aluminum - hydraulic pumps
Sintered Bronze - Porous bronze with a built in oil supply. 2:1 ratio.
10. What characteristics of nylon polyurethanes and phenol laminates affect
their applications?: Heat, , water saturation.
11. What is the hardest and toughest babbitt made from?: Tin (90%)
12. How does overheating affect babitt?: Service life is greatly reduced
13. How is babbitt held in bearing casting?: Holes or slots.
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, Millwright Mechanics Level 2 – Bearings Prep Exams
2025
14. Describe the procedure for pouring a babbitt bearing using a mandrel. (6
Steps): 1. Gather Equipment ( oxyacetylene torch putt pliers, babbitt)
2. Fit the torch with a large tip and melt out the remaining babbitt in the casting
3. Smoke the shaft with a straight acetylene flame.
4. Put a putty dam around the shaft and bearing
5. Hold the babbitt with the pair of pliers
6. Melt it into the bearing with the torch.
15. What must be checked when fitting a bearing? (4 points): surface finish area
of contact, running clearance, lubrication entry, and grooves
16. Describe the purpose of tinning.: To secure a thin skin of babbitt to a metallic
backing.
17. Describe the tools used to fit a friction bearing.: Scraper, files, groove chis-
els.
18. Describe procedure for fitting a bearing.: 1. Chamfer the top edges or cut an
oil groove
2. check bearing for contact by coating mandrel in bluing and rotating mandrel
3. Shave down high spots indicated by bluing
19. Describe the procedure fro shimming a bearing to the correct amount of
clearance.: Insert shims, make sure they do not make contact with the shaft or the
chamfer. Tighten bolts to specs and rotate the shaft. Add shims or realign the cap.
20. Describe the procedure for checking bearing clearance with a dial indica-
tor, Pastigage and lead wire. (3 points): 1. Place indicator on both ends of the
shaft and adjust to acquire an even reading.
2. Insert plastigage and tight cap to proper torque and measure width to determine
clearance.
3. Same way as plastigage
21. Described how preformed bearings are installed and held in place.: Press
preformed bearing into housing with the cap. Or press fit
22. Describe procedure for installing bushings.: Pressure fit or crushed into
housing
23. Describe how thrust is controlled with plain bearings for both low and high
speed applications.: Oil wedges.
24. Describe radial and axial load.: Radial is horizontal load, axial is vertical.
25. Describe the basic design of Kingsbury bearings.: Faces have a minor
pivoted shoes and oil is injected to so during operation the shaft is centered in
clearance accurately.
26. What styles do kingsbury bearings come in? (2 points): Fixed pad and
floating or tilting pads.
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2025
1. What are the principle parts of a friction bearing housing?: Base, Base bolt
slots, cap and cap bolt holes.
2. What are friction bearing housings made from adn what factors influence
the choice of housing?: Cast Iron, Cast Steel, Fabricated Steel.
Choice depends on the Load, The Rotational Speed, the Direction of Pull and the
Support Design
3. How are friction bearing dimensions expressed?: In a fraction of their nominal
size.
4. Do all new bearings of the same shaft size have the same base-to-eye
measurement?: If they are from the same manufacturer.
5. What factors influence the choice of bearings?: Load, Rotational Speed,
Direction of the Pull and support Design
6. What are the applications for the following bearings?
a) Solid Bearings
b) Split bearings
c) Angle bearings
d) Integrated Bearings: a) Where Speed and Load are low. Where load is applied
on the top part of the bearing.
b) Where load is applied on the bottom portion of the bearing. Different bolt numbers
for loads.
c) When load is applied parallel to, or at a slight angle to, the horizontal. Or when the
bearing is mounted on the vertical support
d) Where the bearings are an integral part of the machine.
7. How does friction bearing joint design affect its integrity?: Position of the top
half may affect the bearing tolerances and load positions.
8. What qualities should a good bearing material have? (5 points): Softer than
the shaft material, low coefficient of friction, wear-resistant, a good heat conductor
and remain relatively stable with heat changes, readily available.
9. List Metals generally used in bearing liners and their applications. (5 points)-
: Babbitt - for general use
Brass (copper zinc alloy) - for higher speeds and heavier load than babbit
Bronze (coper tin alloy) - for higher speeds and heavier loading than babbitt
Aluminum - hydraulic pumps
Sintered Bronze - Porous bronze with a built in oil supply. 2:1 ratio.
10. What characteristics of nylon polyurethanes and phenol laminates affect
their applications?: Heat, , water saturation.
11. What is the hardest and toughest babbitt made from?: Tin (90%)
12. How does overheating affect babitt?: Service life is greatly reduced
13. How is babbitt held in bearing casting?: Holes or slots.
1/9
, Millwright Mechanics Level 2 – Bearings Prep Exams
2025
14. Describe the procedure for pouring a babbitt bearing using a mandrel. (6
Steps): 1. Gather Equipment ( oxyacetylene torch putt pliers, babbitt)
2. Fit the torch with a large tip and melt out the remaining babbitt in the casting
3. Smoke the shaft with a straight acetylene flame.
4. Put a putty dam around the shaft and bearing
5. Hold the babbitt with the pair of pliers
6. Melt it into the bearing with the torch.
15. What must be checked when fitting a bearing? (4 points): surface finish area
of contact, running clearance, lubrication entry, and grooves
16. Describe the purpose of tinning.: To secure a thin skin of babbitt to a metallic
backing.
17. Describe the tools used to fit a friction bearing.: Scraper, files, groove chis-
els.
18. Describe procedure for fitting a bearing.: 1. Chamfer the top edges or cut an
oil groove
2. check bearing for contact by coating mandrel in bluing and rotating mandrel
3. Shave down high spots indicated by bluing
19. Describe the procedure fro shimming a bearing to the correct amount of
clearance.: Insert shims, make sure they do not make contact with the shaft or the
chamfer. Tighten bolts to specs and rotate the shaft. Add shims or realign the cap.
20. Describe the procedure for checking bearing clearance with a dial indica-
tor, Pastigage and lead wire. (3 points): 1. Place indicator on both ends of the
shaft and adjust to acquire an even reading.
2. Insert plastigage and tight cap to proper torque and measure width to determine
clearance.
3. Same way as plastigage
21. Described how preformed bearings are installed and held in place.: Press
preformed bearing into housing with the cap. Or press fit
22. Describe procedure for installing bushings.: Pressure fit or crushed into
housing
23. Describe how thrust is controlled with plain bearings for both low and high
speed applications.: Oil wedges.
24. Describe radial and axial load.: Radial is horizontal load, axial is vertical.
25. Describe the basic design of Kingsbury bearings.: Faces have a minor
pivoted shoes and oil is injected to so during operation the shaft is centered in
clearance accurately.
26. What styles do kingsbury bearings come in? (2 points): Fixed pad and
floating or tilting pads.
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