Find a chart of machine screw sizes on the Bolt Depot website. Click Fastener Info on the upper right side of the page, then scroll down and click Machine Screws under the Type-Specific Information heading. The site offers machine diameter and thread charts in U.S. and metric units.
The Bolt Depot website also includes general fastener information such as materials and grades, terminology, abbreviations, and how to identify different types of fasteners. It also offers printable fastener tools, including full size lay-over identification charts.
Machine screws are fasteners often used with nuts or driven into tapped holes and are classified as screws or bolts. They tend to be available in smaller sizes, with diameters ranging up to 3/4 inches.