Millwright Red Seal – Bearings – Study Guide & Practice Questions
A Babbitt bearing percentage refers to its area of contact. This is found by:
a. Feeler gauges
b. Plastic gauge
c. Bluing
d. Lead wire - correct answer ✔✔c. Bluing
A bearing with a "K" it denotes a tapered bearing. This is held in place by:
a. Shaft collar
b. A tapered adapter sleeve
c. Lock nut
d. Thread locker - correct answer ✔✔b. A tapered adapter sleeve
A type of bearing mounted face to face and back-to-back is:
a. Angular contact
b. Conrad
c. Ball
d. Pillow Block - correct answer ✔✔a. Angular contact
A bearing with a code of SKF 6212 has a bore of:
a. 12mm
b. ½"
c. 60mm
d. 62mm - correct answer ✔✔c. 60mm
The bore is indicated by the last two digits of the bearing number.
,Up to 20mm the bore of the bearing is designated as :
00= 10mm
01=12mm
02=15mm
03=17mm
Ex. 6200 ball bearing has bore of 10mm
From 20mm to 80m to find bore multiply the last two figures of the bearing by the number 5.
ex. 6204 ball bearing has bore of 04 x 5 = 20mm
Above 480mm ( # 6296) the bearing size is directly included in the bearing number.
Roller thrust anti friction bearings carry what type of load?
a. Radial
b. Axial
c. Angular
d. Shock - correct answer ✔✔b. Axial
Thrust Load (Axial) - A pure thrust ( axial) load means there is no radial load. All forces run
parallel to shaft axis.
examples are ball and needle thrust bearings.
What do you use to check the clearance of a spherical roller bearing?
a. Feeler gauge
b. Babbitt
c. Plastigauge
, d. Bluing - correct answer ✔✔a. Feeler gauge
What temperature (in Fahrenheit) is a bearing to be heated to in an oil bath, prior to
installation?
a. 248 to 250
b. 260 to 262
c. Always below 240
d. Always above 260 - correct answer ✔✔a. 248 to 250
What temperature (in Fahrenheit) is Babbitt poured at?
a. 650 to 700
b. 800 to 1000
c. 300 to 325
d. 575 to 775 - correct answer ✔✔a. 650 to 700
Pour point - from 343 to 371*C (650 to 700*F)
complete melting point - from 275-285*C ( 495 to 545*F)
Complete solidification point - from 25- 28*C ( 40 - 50F ) below the complete melting point .
What is "creep" in a bearing?
a. The very slow rotation of the outer race
b. The movement of the bearing as it rotates out of the housing
c. A condition that allows for expansion of the pillow block due to heat
d. The very slow rotation of the needles in a needle bearing - correct answer ✔✔a. The very
slow rotation of the outer race
What are gib joint bearings suited for?
A Babbitt bearing percentage refers to its area of contact. This is found by:
a. Feeler gauges
b. Plastic gauge
c. Bluing
d. Lead wire - correct answer ✔✔c. Bluing
A bearing with a "K" it denotes a tapered bearing. This is held in place by:
a. Shaft collar
b. A tapered adapter sleeve
c. Lock nut
d. Thread locker - correct answer ✔✔b. A tapered adapter sleeve
A type of bearing mounted face to face and back-to-back is:
a. Angular contact
b. Conrad
c. Ball
d. Pillow Block - correct answer ✔✔a. Angular contact
A bearing with a code of SKF 6212 has a bore of:
a. 12mm
b. ½"
c. 60mm
d. 62mm - correct answer ✔✔c. 60mm
The bore is indicated by the last two digits of the bearing number.
,Up to 20mm the bore of the bearing is designated as :
00= 10mm
01=12mm
02=15mm
03=17mm
Ex. 6200 ball bearing has bore of 10mm
From 20mm to 80m to find bore multiply the last two figures of the bearing by the number 5.
ex. 6204 ball bearing has bore of 04 x 5 = 20mm
Above 480mm ( # 6296) the bearing size is directly included in the bearing number.
Roller thrust anti friction bearings carry what type of load?
a. Radial
b. Axial
c. Angular
d. Shock - correct answer ✔✔b. Axial
Thrust Load (Axial) - A pure thrust ( axial) load means there is no radial load. All forces run
parallel to shaft axis.
examples are ball and needle thrust bearings.
What do you use to check the clearance of a spherical roller bearing?
a. Feeler gauge
b. Babbitt
c. Plastigauge
, d. Bluing - correct answer ✔✔a. Feeler gauge
What temperature (in Fahrenheit) is a bearing to be heated to in an oil bath, prior to
installation?
a. 248 to 250
b. 260 to 262
c. Always below 240
d. Always above 260 - correct answer ✔✔a. 248 to 250
What temperature (in Fahrenheit) is Babbitt poured at?
a. 650 to 700
b. 800 to 1000
c. 300 to 325
d. 575 to 775 - correct answer ✔✔a. 650 to 700
Pour point - from 343 to 371*C (650 to 700*F)
complete melting point - from 275-285*C ( 495 to 545*F)
Complete solidification point - from 25- 28*C ( 40 - 50F ) below the complete melting point .
What is "creep" in a bearing?
a. The very slow rotation of the outer race
b. The movement of the bearing as it rotates out of the housing
c. A condition that allows for expansion of the pillow block due to heat
d. The very slow rotation of the needles in a needle bearing - correct answer ✔✔a. The very
slow rotation of the outer race
What are gib joint bearings suited for?
