muttern

Muttern is the German term for nuts used as fasteners in mechanical engineering. The plural Muttern refers to the individual pieces collectively; the singular is die Mutter. In everyday German, die Mutter also denotes a female parent, whose plural is Mütter. In technical contexts and product catalogs, Muttern denote the threaded, female half of a bolt-and-nut assembly, designed to fasten parts together.

Common types of Muttern include the hex nut (Sechskantmutter), which is the standard shape for use with common bolts; flange nuts (Flanschmuttern) with an integrated washer-like flange; lock nuts (Sicherungsmuttern) that resist loosening, including varieties with nylon inserts (Nylonsperrmutter); wing nuts (Flügelmuttern) for hand-tightening; and jam nuts (Unterlegmuttern) used to lock pieces together. Materials range from carbon steel and stainless steel to brass and aluminum, with finishes such as zinc-plated, hot-dip galvanized, or black oxide. Muttern are standardized for metric threads (ISO M sizes) and other national standards, with varying thread pitches from coarse to fine. They are designed to be used with corresponding bolts or threaded rods.

Muttern play a central role in a wide range of applications, from automotive and industrial machinery to consumer products and furniture assembly. Typical installation requires a wrench or socket tool, and sometimes a torque specification is provided based on size, material, and thread type. The term Muttern in German thus principally refers to the hardware fasteners, while its homograph Mütter refers to mothers in everyday language.