In eStatement Studies you'll find Financial Ratio Benchmark (FRB) figures, broken down by US Region and revenue quartile, for a very large number of industries.
Look here for smaller and specialized industries, like Adhesive Manufacturing or Automobile Driving Schools.
Business Source Premier provides the full text of more than 2 thousand business publications, including more than 1,000 peer reviewed journals. It is a comprehensive database that covers all disciplines of business including management, finance, marketing and international trade. It also contains company, industry and country reports, SWOTs and market research reports.
ABI/Inform Trade & Industry contains business and in depth company and industry articles from over 2,000 scholarly, trade and news publications. It also includes reports from major and smaller, niche industries that contain information for entrepreneurs and financial data perfect for marketing and business plans. Users can set up alerts, establish RSS feeds, and share articles. Users who establish a free account can save and organize research and tag articles which can be shared with other users.
Use these resources to find ratios for US industries. Find more direction on using these databases in the other boxes on this page.