toe spike screws

Hey all,
I just got some toe spikes and I was wondering how long are the screws that you use. I think the ones I have may be too long.

The ones that came with my RussRep spikes were WAY too short. The soft cushion of the sole didn't allow them to grab. I actually used about 1.5 inch long lag screws. If you put them in parallel with the sole, they'll stay inside the cushion area and not in your feet or the floor. Also, I used a little goop on the screw as I screwed it in to make sure they don't back out.

Mine were about 1" long.

Thanks guys!