Great filters and I love the lens hood too.
I read several different reviews on similar products. Ultimately I settled on these. Glad I did appears to be good quality.
If you are having a problem this is how i do it for problem free install. I lay the filter over the threads and then turn them counter clockwise until the filter lays flat once I here of feel the end threads skip over each other then I start to turn them clockwise. But do it slowly as they are very easy to cross thread no matter the filter brand.
IF you do as I said you should have no problem getting these in place.