I've read variations on what hardware to use in bolting the toilet tank to the bowl. From a top down sequence with optional/variation items indicated in parentheses:
- metal washer under bolt head seems discouraged due to possible leaks, but some feel it will provide more even pressure on the rubber washer
- some avoid anything (nut, washers) between the tank and bowl, perhaps to avoid clearance issues between the tank and bowl; this means the lower nut is both providing the pressure for the seal in the tank and securing it to the bowl
- the rubber washer under the bowl seems optional, maybe to help mitigate overtightening/cracking the bowl
What sequence is recommended?