I've used the Y000 bit pretty extensively on the 7 Plus, and it's the same bit that we used for all our guides and teardowns for both phones. It also works for the Watch, which has much smaller screws. I'm afraid we don't make anything smaller!

I will say that the tri-point screws sometimes require more pressure than I'm accustomed to, in order for the driver to bite. I think it's because the heads are so shallow; the driver needs to be really snug and absolutely on-axis in order to get any traction on the screw head.

I'd suggest giving it another whirl! On the off-chance you got some kind of defective bit (it's very rare, but it happens), reach out to our customer service team for a replacement. Good luck!