Visual Testing (VT) Practice Exam

Which measurement indicates the roughest surface finish?

1. 64 µin.

2. 150 µin.

3. 250 µin.

4. 380 µin.

The correct answer is: 380 µin.

The measurement that indicates the roughest surface finish is indeed associated with a higher numerical value, as surface roughness is typically represented in microinches (µin) or micrometers, where a larger number corresponds to a rougher finish. In this context, a value of 380 µin would signify a greater amount of surface irregularity or texture compared to the other options. This larger number represents more pronounced peaks and valleys on the surface, leading to a finish that feels coarser or appears less smooth. In manufacturing and machining, this understanding is crucial, as different applications require different levels of surface finish for optimal performance. The values provided in the other choices represent smoother finishes, each with lower measurements than 380 µin, which indicates progressively finer and less rough surfaces. Thus, the choice that indicates the roughest surface finish is the highest measurement, which in this case is 380 µin.