Replacing one hole (Mono mixer taps)

I think due to constant use the nut which holds my present mono mixer taps on my kitchen sink, tends to become loose, this then causes the tap to become loose. I have bought a new mono mixer tap as I was going to replace the existing one.

I am now unsure if it's worth replacing the taps, given it's the nut that works itself loose. I did tighten the nut up earlier and the taps are pretty stable.
My question is do I have to use the same nut on new replacement that's holding the taps/fixure in place? If so, I think I'll get a refund on the new tap as it is defeating the object, if the exsisting nut once again works its way loose again.

I know what I'm trying to say lol I hope you do
Many thanks

Hi

It depends. If the bolt is all rusted up then you would prob need to remove/replace the tap anyway.

I'd get a set of dedicated spanners to try tightening it up. Screwfix.

Thanks Fleeting, regarding replacing with the new taps, would this mean I would have to use the existing nut to hold the tap in place? I've checked the new taps and didn't see a nut, some washers (horseshoe) of course but no nut as such.
Thanks

You should have a long brass nut with the new mono, if not take it back and get a refund. you dont use existing nut.

Tighten the one you have now properly. finger tight aint enough

get one of these

If the tap is working loose put a jamb nut on it too though it is usually the bottom plate that bends and it becomes loose.
Most taps are made of cheap junk metal now. Changing them will only make it better for a while. It's the way of the world i'm afraid