A: Size wise it’s more like 8D.
A: Yes you can get them the same length. They have never bent on me and if you make mistake take it out and put it back with ease
A: In length, like an 8d and in girth, more like a 12d, but with a whole lotta holding power.
A: There are approximately 870 screws in a 10lb box. This information is included in the product specifications for your convenience.