In shaft alignment, what is meant by parallel (offset) misalignment?

• A. The shafts intersect at a point
• B. The shafts are parallel but not collinear, causing a lateral offset
• C. The shafts are at right angles
• D. The shafts have the same centerline

Answer: (B)

Parallel (offset) misalignment means the two shaft centerlines run in the same direction but do not share the same line; there is a constant sideways distance between them along the length. This describes shafts that are parallel but offset, so they are not collinear. It’s different from angular misalignment (where the shafts are angled relative to each other and their centerlines would intersect) and from perfect alignment (where the centerlines coincide). This type of misalignment causes side loads and vibration unless the offset is corrected so the centerlines line up.