WTMA Common Tools and Fasteners 3

Question 1

What is the function of a lock washer placed under a bolt head?

Accepted Answer

Prevent the fastener from loosening due to vibration

Answer

Lock washers (split or toothed) bite into the fastener and mating surface to resist rotational loosening from vibration.

Question 2

When would you use a reamer instead of a drill bit?

Accepted Answer

To enlarge and precisely finish an existing hole to exact size

Answer

A reamer is used after drilling to bring a hole to a precise final diameter with a smooth finish.

Question 3

A hex key (Allen wrench) engages which type of fastener drive?

Accepted Answer

Internal hexagonal socket (hex socket)

Answer

Hex keys fit into internal hexagonal (6-sided) recesses found in set screws, socket head cap screws, and similar fasteners.

Question 4

What does a higher grade number on a metric bolt (e.g., 10.9 vs 8.8) indicate?

Accepted Answer

Higher strength and hardness

Answer

Higher metric bolt grade numbers (like 10.9 or 12.9) indicate greater tensile strength and hardness compared to lower grades like 8.8.

Question 5

Which type of pliers is best suited for gripping rounded objects like pipes?

Accepted Answer

Tongue-and-groove (Channellock) pliers

Answer

Tongue-and-groove pliers (like Channellocks) have curved jaws and an adjustable pivot that provide a wide opening and good grip on rounded objects.

WTMA - Wiesen Test of Mechanical Aptitude Practice Test