If you only need a small number of wire clamps, here's a quick way to satisfy that need, 3D print them. I never have the right size wire clamp on-hand. To resolve that issue, I just print the sizes and quantities I need at the time.

Here is my design that includes a clamp suitable for the following three wire sizes, 4, 6 and 8mm. The mounting screw hole is optimised for a 3.5mm countersunk self-tapping screw.

I used PLA+, but most materials are suitable to make a clamp. So, choose filament type based on environmental conditions and clamp strength/flexibilty required.

My print is made in eSUN PLA+ 1.75mm White/Blue/Red filaments, with 0.2mm layer height and 100% infill on a Bambu X1 Carbon printer. No supports required. Brim recommended.

I hope you can find this print useful, too.

Remember to leave me some feedback or even a tip to keep me enthused to make more of these drawings.