I wouldn't put one of those on anything bigger than an .049. I have used 3 of those types on three different planes, and they all did the same thing, threw the screws out and they were aluminum. The problem is when the prop holes are cut out, you can't tell if their balanced, if they are out of balance, which they will be, the screws can't stay in. One came apart in the air, and shattered the prop. NOT GOOD.
I will say though, they are pretty, just design a better way to hold them together.