WTMA Common Tools and Fasteners 2 — Questions and Answers
Question 1: Which type of screwdriver bit is required for a Torx fastener?
- Phillips
- Star-shaped (6-point) (Correct answer)
- Flat blade
- Square (Robertson)
Correct answer: Star-shaped (6-point)
Torx fasteners have a 6-pointed star recess that requires a matching star-shaped Torx bit.
Question 2: A bolt has a tensile strength rating. What does this rating indicate?
- The maximum torque it can absorb
- The maximum pulling force before failure (Correct answer)
- The hardness of the bolt material
- The number of times it can be reused
Correct answer: The maximum pulling force before failure
Tensile strength is the maximum axial pulling (tension) force a bolt can withstand before breaking.
Question 3: What is the primary purpose of a tap wrench?
- Tightening pipe fittings
- Cutting internal threads in a hole (Correct answer)
- Removing broken bolts
- Measuring hole diameter
Correct answer: Cutting internal threads in a hole
A tap wrench holds and turns a tap to cut internal (female) threads inside a drilled hole.
Question 4: Which fastener type is designed to be installed from one side without access to the back?
- Carriage bolt
- Hex cap screw
- Pop (blind) rivet (Correct answer)
- Machine screw
Correct answer: Pop (blind) rivet
Pop rivets (blind rivets) are designed for one-sided installation where the back of the joint is inaccessible.
Question 5: A mechanic uses a breaker bar instead of a ratchet. What advantage does the breaker bar provide?
- It fits more socket sizes
- It provides greater torque leverage without a ratcheting mechanism (Correct answer)
- It prevents over-tightening
- It works in both directions automatically
Correct answer: It provides greater torque leverage without a ratcheting mechanism
A breaker bar's longer handle provides more torque leverage for loosening stubborn fasteners, without the internal ratchet that could flex or break under high loads.
Question 6: What does 'SAE' mean when referring to wrenches and sockets?
- Standard Alloy Engineering
- Society of Automotive Engineers (inch-based sizing) (Correct answer)
- Steel Alloy Equipment
- Socket and Allen Equipment
Correct answer: Society of Automotive Engineers (inch-based sizing)
SAE stands for Society of Automotive Engineers, and SAE tools use inch-based measurements (e.g., 1/4", 3/8").
Question 7: Which tool is used to measure the outside diameter of a shaft accurately to thousandths of an inch?
- Vernier caliper
- Outside micrometer (Correct answer)
- Feeler gauge
- Dial indicator
Correct answer: Outside micrometer
An outside micrometer is designed to precisely measure the external diameter of cylindrical objects to 0.001 inch or finer.
WTMA Common Tools and Fasteners 2
Which type of screwdriver bit is required for a Torx fastener?