Clamp hooks for a 15.5mm (5/8") diameter rail

We have an Ikea wall mounted dish drainer. The wall mounting is a long rail from which the dish drainer hangs and a lot of left over rail and S shaped hooks so that cups, or strainers, etc can be suspended from the rail.
I found the supplied hooks (S-shaped Stainless Steel) annoying as they were a very loose fit and easily moved out of position when casually hanging something from them. I wanted hooks that 'held their position' and didn't require so much concentration - or hand eye coordination