What tool for dismantling kitchen/bathroom pillar taps?

[<Use-Author-Supplied-Address-H]

Dear All, What tool do you recommend for unscrewing the top hat nut on kitchen/bathroom pillar taps where it has become corroded on? Basin Wrenches seem to be suggested for the back nuts as are the special doubled-ended box spanners++ for both basin taps and the larger bath taps. If the answer is a set of (box) spanners, what are the common top hat nut sizes?

Thanks Tom Crane.

[++] eg.

Ps. The email address in the header is just a spam-trap.

[Alexander Lamaison]

I can't vouch for a particular tool but I can highly recommend WD-40 penetrant spray [1]. This stuff is bloody amazing. It's loosened some joints for me that looked totally hopeless and weren't responding to regular WD-40 and a whole load of straining. Spray on, make a cup of tea, then give the joint a good tug.

[1]

Alex

[The Medway Handyman]

There are box spanners specifically made for back nuts