"Heartily agree with Alex regarding weight. Lightweight plastic would be better.  If they were easily stackable no-lids is better. Lids get in the way on the job-site, get thrown away or damaged.  I also use a lot of buckets now, rectangular boxes would be more space efficient and would get rid of the bucket lids. So, here's an idea for someone. Oh yea, milk crates have already been invented. Make them solid (no holes for parts to fall out) and sell them at the home centers. Maybe even make them matching milk crates so they can be used in combination. "