Nuts for General Applications: Machine Screw Nuts, and Hex, Square, Hex Flange, and Coupling Nuts (Inch Series)
Purpose of ASME B18.2.2-2022
ASME B18.2.2-2022, titled Unified Inch Screw Threads (UN and UNR Thread Form), is a standard developed and published by the American Society of Mechanical Engineers (ASME). Its primary purpose is to define the dimensions, tolerances, and specifications for nuts used with inch-based threaded fasteners, such as machine screws, bolts, and studs. The standard ensures interoperability, strength, and reliability of nut and bolt assemblies in mechanical and structural applications by providing standardized designs for various nut types, including hex, square, and heavy hex nuts. It aims to promote safety, consistency, and compatibility in fastening systems, reducing risks of thread mismatch, stripping, or failure under load.
Typical Use
ASME B18.2.2-2022 is typically applied in the design, manufacturing, and assembly of mechanical and structural systems across industries such as construction, automotive, aerospace, and manufacturing. Common applications include:
Engineers, manufacturers, and quality control professionals use the standard during project phases to:
The standard is often used alongside other ASME B18 series standards (e.g., B18.2.1 for bolts) and is referenced in engineering drawings, procurement specifications, and industry codes to ensure compatibility and performance. The 2022 edition includes updates such as revised dimensional tolerances, clarified thread specifications, and alignment with modern manufacturing practices, reflecting advancements in fastener technology and quality control.
| SDO | ASME: American Society of Mechanical Engineers |
| Document Number | B18.2.2 |
| Publication Date | Jan. 1, 2022 |
| Language | en - English |
| Page Count | 209 |
| Revision Level | |
| Supercedes | |
| Committee |