Millwright Level 1 Practice Exam

What is one advantage of rolled threads over machined threads?

1. Lower manufacturing cost

2. Increased tensile strength

3. Easier to manufacture

4. More aesthetic appearance

The correct answer is: Increased tensile strength

One distinct advantage of rolled threads over those that are machined is the increased tensile strength. This phenomenon occurs because rolling forms the threads through a process that displaces material, aligning the grain structure in a way that enhances mechanical strength. The rolling process creates a more uniform and compact thread profile, which can handle greater stress and loads without failing. In contrast, machining threads involves cutting away material, which can weaken the structural integrity of the thread due to the disruptions in the grain flow and potential micro-cracking introduced during cutting. Therefore, the rolled threads provide improved performance characteristics, particularly in applications where high strength and durability are critical. The other options, while they may have some merit in different contexts, do not capture the primary technical advantage associated with rolled threads as specifically as the increase in tensile strength does.