Introduction to Threaded Fasteners

Threaded fasteners are used in virtually all types of mechanical equipment; consequently, threaded fastening technology is crucial for ensuring the reliability of mechanical systems. Due to their widespread use, threaded fasteners have become highly standardized components. Universal standards-such as ISO and JIS-provide catalogs of parts (including bolts, nuts, and washers) classified by dimensions (nominal diameter, length, head shape, etc.) and strength grades. As a result, threaded fasteners of any specification are easily accessible simply by selecting them from these standards. This has transformed threaded fasteners into highly convenient components that can be "designed" through a process of "simple selection."