Source of information on ferrous and non-ferrous metals and materials technology. Includes 30 ASM Handbook volumes, supplements with searchable tabular data.
"Buyer's Guides" are specialized directories for industry. Although some do include the suppliers catalogs, most are actually indexes for finding vendors. Online "Trade magazines" (news and expert advice) usually have these specific to their fields.. Although a keyword search in any web search engine will often find something of use, why buyer's guides remain popular is the categorization features and the in-depth expertise behind them.