I bought these hinges to replace the original ones on a resin toilet seat originally bought from Argos. I had read on here other reviews from people who had to redrill the mounting holes to get them to fit, but I took a chamce and ordered them anyway.
Well they went straight on, fitting perfectly and are virtually identical to the original ones. However, the reason they had to be replaced was that the mounting hole for the threaded stud on one of the old hinges had stripped. This is apparently a common fault. The old hinges used to repeatedly undo themselves - the threaded stud kept loosening. I would recommend therefore that you also purchase replacement conical section washers:4 RUBBER NON SLIP TOILET SEAT HINGE FITTINGS FOR FIXING LOOSE TOILET SEATS. FOR CHROME AND BRASS HINGES ON WOODEN, RESIN, PLASTIC, MAHOGANY,WHITE, OAK & NOVELTY SEATS.
I suggest you "shop around" before buying them however. I managed to find them cheaper in a set containing just the 2 rubber conical washers.
The washers originally supplied with the hinges are made from a slippery plastic material and are likely to cause the above fault. I've fitted the rubber conical washers from tfm-services and so far they seem to have solved the problem - I would also recommend cleaning and drying the underside of the seat hing mounting holes so that the rubber gets a good grip on the porcelain. The only reason I didn't give these hinges 5 stars is that they are made from the same soft zinc alloy as the originals which is part of the reason for the problem I have described.
PS. I have had to edit this review with a downgrade to 3 stars, and am still being generous. Since fitting these hinges, the problem I described with the main mounting stud loosening itself off is cured. But the small screws holding the upper half of the hinge to it's base plate are now displaying the same fault.
The problem is that the manufacturers have used countersunk head screws. Under the head of these screws is a lock or star washer which should stop them loosening. However the tapered countersunk head means that the lock washer hasn't got a flat surface to grip on. My solution was to use thread lock:Loctite 243 Lock 'n' Seal Fast Acting Thread Lock and Sealant 3ml
(£3.19 from LG Tool Supplies at time of writing - very fast service) which has cured the problem.
For anyone reading this and thinking "Why didn't he just fit a new seat?". If I had, I would still have had all the same problems to solve as these hinges seem to be standard on Chinese made seats (ie. virtually all of them).