Some might say it has a screw loose, but things are really pretty snug at Fastenal. The company operates about 2,500 stores in all 50 US states as well as in Canada, Mexico, Central America, Asia, and Europe. Its stores stock about 690,000 products in about a dozen categories, including threaded fasteners (such as screws, nuts, and bolts). Other sales come from fluid-transfer parts for hydraulic and pneumatic power; janitorial, electrical, and welding supplies; material handling items; metal-cutting tool blades; and power tools. Its customers are typically construction, manufacturing, and other industrial professionals. Fastenal Company was founded by chairman Bob Kierlin in 1967 and went public in 1987.