Industrial Resource Network

Directory of suppliers, with a search engine and large index page.
InternationalBrokers.org - Global B2B portal connecting buyers with suppliers worldwide through company listings, trade leads, product catalogs, and full profiles. A business to business directory of companies from the United States and around the world.
Internet Reference Library - Annotated listing of business-related reference links.
Kellysearch - Searchable directory of suppliers of products and services related to industry, manufacturing and engineering. Directory of products, equipment and services for companies and professionals.