I needed an M10 to M6 thread adapter for a project. At $1 each, shipping was pretty pricey, but unfortunately, it was pretty much the only product I could find that did the job. my test parts. It tightens fine, but you may need to put some threadlock on it and tighten it a bit to keep it from loosening.
πͺ Strong and Versatile: National Hardware N222 406 Square Bolts for Secure Fastening
7 Review
π Carriage Prime Line Products GD52103
6 Review
π© Hard-to-Find Quick Fastener 014973253790 - 4 Piece Set
7 Review
π© 5-Pack of M8x60mm Stainless Steel External Hex Expansion Bolts by Yasorn
10 Review