Use a crescent spanner to tighten that loose bolt.
crescent spanner
idiomAn open-end adjustable spanner with a worm-drive thumbwheel. When the term adjustable spanner or adjustable wrench is used, this type (branded with any of many brands) is usually the type meant.
Origin
disputed originA genericization of the trade name of a company famous for making them (although it did not invent them); details are at Wikipedia. The trademark is still protected, and this genericized term is only informal and loose. Compare kleenex and coke.
I could not find the right size wrench, so I used a crescent spanner to finish the repair.
The mechanic reached for his crescent spanner, carefully adjusting the thumbwheel to fit the unusual nut size before applying steady pressure.