Most,if not all,toilet seats are secured by a couple of secure points of various types.OK! But are the diameters or circumferences of these holes going through the ceramic bowls a standard size? The reason I ask is that the new seat fittings or fixings I've just bought, don't fit trough the ceramic holes (which are too small)and I wondered if a 'standardization' or something was brought in to 'cancel- out' variations,etc. and if there is a solution to my problem. Are there smaller size 'bushes' available and if so,where? This is a 'top fitting' toilet seat,or as I thought a 'quick release'toilet seat and as I've just bought the thing, I don't want to resort to a long bolt and wingnut!
So the old existing seat fittings fitted, but the new one don't?
One way to determine any size difference is try a nut say 10 mm for explanation purposes. If it screws onto the old fitting, but won't on the new, the new is a larger diameter.