[T1] Why the Hook Moves at the Tip

Tape Hook Thickness and Play (Movement)

You may notice that the T1 blade hook can move between two positions - one extended, one retracted.  This is intentional to account for the width of the tape measure blade (around 1mm) which correlates to the travel the blade can move (around 1mm).  This is a standard feature on almost every tape measure blade and is a mechanical way to compensate for the thickness of the The thickness of the tape hook is compensated for mechanically.

Tape Hook Extended (Exterior Measurements)

Tape Hook Pushed in (Interior Measurements)