Thread Types for Screws and Fasteners
Thread Types for Screws and Fasteners
Thread Types for Screws and Fasteners
Thread Type | Description | Usage |
---|---|---|
Unified Thread Standard (UTS) | Standard thread form used in the United States for screws and nuts. | General-purpose, wide range of applications. |
Metric Thread | Thread form based on the metric system, widely used in Europe and other parts of the world. | International standard, precise and reliable. |
Unified National Thread (UNC) | Coarse thread series used for general applications where high vibration resistance is not required. | General-purpose screws, bolts, nuts. |
Unified National Fine (UNF) | Fine thread series used where higher strength or resistance to stripping is needed. | Aerospace, automotive, high-stress applications. |
Unified Miniature Thread (UNM) | Small-diameter thread series used in precision instruments and small devices. | Electronics, medical devices, small machinery. |
British Standard Whitworth (BSW) | Obsolete thread standard once used in the UK and other Commonwealth countries. | Historical applications, restoration projects. |
British Standard Fine (BSF) | Obsolete fine thread standard once used in the UK and other Commonwealth countries. | Historical applications, restoration projects. |
Acme Thread | Truncated thread form with a 29-degree angle, used in applications requiring high strength and wear resistance. | Machine tools, jacks, presses. |
Buttress Thread | Thread form with one side flat and the other side angled, used for applications requiring high axial load capacity. | Lathes, milling machines, vices. |
Knuckle Thread | Thread form with rounded crests and roots, used for easy assembly and disassembly. | Adjustable mechanisms, furniture. |