Exam 100 Questions And Correct Answers

Master Millwright Certification Practice Exam 100 Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• Which type of alignment is typically used for a horizontal shaft

connected to a motor?

• Angular alignment
• Parallel alignment
• Combination alignment
• Offset alignment

Answer: Combination alignment

Rationale: Combination alignment accounts for both angular and

parallel misalignment, which is common in horizontal shaft installations.

• What is the primary purpose of a key in a shaft and hub assembly?
• Reduce vibration
• Transmit torque 1 / 4

• Prevent shaft bending
• Lubricate the assembly

Answer: Transmit torque

Rationale: A key fits into slots on the shaft and hub, allowing torque

to be transmitted without relative motion between the two components.

• Which measuring tool is most accurate for checking shaft alignment?
• Tape measure
• Ruler
• Dial indicator
• Spirit level

Answer: Dial indicator

Rationale: Dial indicators can measure small deviations in shaft

alignment, providing precise readings for alignment adjustments.

• What type of bearing is best for supporting radial loads at high

speeds?

• Plain bearing
• Ball bearing
• Thrust bearing
• Tapered roller bearing

Answer: Ball bearing

Rationale: Ball bearings are designed to handle radial loads

efficiently at high rotational speeds. 2 / 4

• When using a laser alignment tool, what is the main advantage over

traditional methods?

• Lower cost
• Higher precision and faster setup
• No need for shaft coupling
• Can measure vibration

Answer: Higher precision and faster setup

Rationale: Laser alignment tools provide accurate readings quickly,

reducing downtime and human error.

• What is the main function of a coupling in machinery?
• Reduce friction
• Absorb heat
• Transmit power between shafts
• Support shaft ends

Answer: Transmit power between shafts

Rationale: Couplings connect two rotating shafts, transmitting

torque while allowing some misalignment or movement.

• Which type of coupling can accommodate angular and parallel

misalignment?

• Rigid coupling
• Sleeve coupling
• Flexible coupling
• Gear coupling 3 / 4

Answer: Flexible coupling

Rationale: Flexible couplings allow small angular, parallel, and axial

misalignments without causing excessive wear.

• In machining, what does the term “runout” refer to?
• Shaft speed
• Deviation from true rotation
• Lubrication type
• Tool sharpness

Answer: Deviation from true rotation

Rationale: Runout is the measure of how much a rotating shaft or

tool deviates from a perfect circle.

• Which lubrication method is commonly used for high-speed spindle

bearings?

• Grease lubrication
• Oil bath or circulating oil
• Manual oiling
• Water cooling

Answer: Oil bath or circulating oil

Rationale: High-speed spindle bearings require continuous oil

lubrication to prevent overheating and wear.

• What is the most common cause of shaft vibration in rotating

equipment?

• Corrosion
• / 4