[T1R] Why does the tape hook move?

The tape measure hook moving back and forth is by design, and an intentional detail added to nearly every tape measure made. The distance the hook travels is equal to the thickness of the hook metal itself, which on the T1R is 0.05" (1.27 mm). This lets the tool display an accurate measurement whether you are measuring an inside or an outside dimension.

Measuring an Outside Dimension

When measuring the outside of a surface, hook the metal end over the edge. The hook slides away from the case, creating a gap equal to the hook's thickness. That gap means you do not need to account for the hook in your measurement.

Measuring an Inside Dimension

When measuring the inside of a surface, push the hook against the inside of the material. The hook moves toward the case, becoming part of the measurement.

This Is Not a Defect

A hook with a small amount of play is working as intended. A hook that is bent, loose in more than one direction, or does not return to position is a different matter — see [T1R] Broken Parts.