Vabowman

I still have a few heads that have bleds that won't tighten down. The head is all the way on and the blades still rattle... Not all of them do it, but 2 or 3 do. It does it on any arrow, not just the Axis. I called ST and they told me to make sure I was using the flat side of the washer and I am, but it still doesn't fix it. I can take the blades out and put them in a different head and the rattle is gone, it's a few heads no matter what blades on in em.. Think it maybe a factory deffect on the furrel??