I like the colours alot, and the backfround is really nice (especially with the shadow), but I think a little (just a very little) less light might have helped with the glare on the metal.
I think this is an excellent macro.. I like the strong diagonal created by the wood grain and the opposing diagonal created by the shadow in this image. I'm not sure what the true color of this screw is, but the golden yellow tint could possibly offer some better contrast against the wood if it was chrome... The exposure is also just a tad hot... - setzler
Just as an after thought, this was a cool idea, but imagine if you had done a city of them using different sized screws, hence brass city, nice idea, I like it!
I like everything about this shot, good composition and balance. The textures and focus are excellent. I even like the shadow which leads me right to the screw. Great job. DPz