Screw - still life

Part of a final assignment in my Drawing I class from the spring. We were each given a normal hardware screw to draw as part of final homework.
It was supposed to fill up the page, rendered in charcoal.

Mine ended up not looking quite like the original still life, but I'm still happy with it anyway. The threads are not close enough together and it is a bit dark in spots. The shadow also doesn't match as well as it should.

Materials used:

Standard charcoal - b & w (sorry don't remember the brand!)
Stonehenge weighted paper 30" x 22"- (I think anyway...)
Chamois cloth - (blending)
Blending Stump - (obviously )
I also wore gloves to keep everything nice and neat.