
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.