Have you ever done a DIY project and used a tape measure, and doubt your reading because the clasp at the end seems to wiggle a little bit? Happens all the time. It seems like the manufacturer would tighten that clasp eventually and fix it, but they just ignore it. Not so! The clasp is actually meant to move.
Why would you want that clasp to move? The metal clasp on the end moves slightly back and forth to ensure accurate measurements. The end moves to compensate for its own thickness, allowing an accurate reading. Most tape measures are divided into 1/32 inch increments for the first few inches to ensure accuracy.
If you are working with someone else on a project, though, check your tape measures and make sure they are calibrated. It is possible for them to be slightly different and cause problems in the accuracy of your project.