Gängbeteckningar

Gängbeteckningar, or thread designations, are standardized ways of describing screw threads. They provide essential information for selecting the correct fasteners and ensuring proper assembly. A typical gängbeteckning includes details about the thread's nominal diameter, pitch, thread form, and tolerance class.

For metric threads, the gängbeteckning often begins with the letter "M," indicating metric ISO thread. This is followed by the nominal major diameter in millimeters, such as "M10" for a 10 mm diameter thread. If the pitch is not the standard coarse pitch for that diameter, it will be specified after the diameter, separated by a hyphen. For example, "M10x1.25" denotes a 10 mm thread with a 1.25 mm pitch.

Unified Thread Standard (UTS) gängbeteckningar are also common, especially in North America. These typically use a number to denote the diameter (e.g., #10) or a fractional inch (e.g., 1/2). The thread per inch (TPI) is then specified, often with a space or hyphen. For instance, "1/2-13 UNC" indicates a 1/2 inch diameter thread with 13 threads per inch, using the Unified National Coarse thread form. The "UNC" or "UNF" suffixes specify whether it's a coarse or fine thread.

In addition to diameter and pitch, gängbeteckningar can include information about the thread's tolerance class. This specifies the permissible deviation in the thread's dimensions, ensuring interchangeability and proper fit between mating parts. Different tolerance classes are used for internal and external threads. Understanding these designations is crucial for engineers, mechanics, and anyone involved in mechanical assembly to ensure the correct and secure fastening of components.