Subject: What types of iron products would be good for doing experiments on rusting?

I'm a high school junior and am doing a research project on 
reduction potentials and their relationship to corrosion.  I'm 
using iron samples - some left in test tubes with pure oxygen, 
some left open to the air in the lab, some submerged in salt 
water, some in tap water, some in distilled water ...So far, 
I've found that certain nails, food cans, and razors rust 
well...can you recommend any other iron objects that would be 
condusive to oxidation in this experiment?  In other words, I'm 
looking for iron products available in the marketplace, etc.  
that are NOT coated or designed to PREVENT rust.
Any help (even suggestions on my experimental design) would be 
greatly appreciated.
Thanks.

Re: What types of iron products would be good for doing experiments on rusting?