Good Morning Nigel,

Thank you for your question and photo, indeed the hole is made slightly larger than needed, this is to prevent over-tightening at the factory and the pruners not being able to be opened. the only hints we can give is that all manual secateurs/pruners and handheld tools are to re-tighten screws and nuts after each use. We also recommend oiling the blade after each use to help with the longevity of the product, as well as sharpening periodically.

Hope this helps