Gewinden

Gewinden, in mechanical engineering, refers to screw threads—the helical ridges around a cylinder or inside a hole that mate with a nut or bolt. They form detachable or adjustable joints and allow conversion of rotational motion into linear movement. Threads are described by their form, pitch, and diameter and occur as external threads (on fasteners) and internal threads (in tapped holes or nuts).

Common thread forms include metric ISO threads, imperial Unified threads (UNC/UNF), and Whitworth (BSW). For power transmission and advanced applications, trapezoidal (ACME) and buttress profiles are used. The geometry centers on the major diameter (crest to root) and the pitch diameter (the size where thread engagement is defined), with pitch determining how far the nut advances per turn. Tolerances and clearance govern fit and performance, ranging across standard classes for both external and internal threads.

Manufacturing methods span thread cutting (screw taps and single-point threading on lathes), thread rolling (cold-formed threads with high strength), milling, grinding, and increasingly additive manufacturing for complex geometries. Quality control employs go/no-go gauges, thread micrometers, and optical measurement to verify pitch, diameter, and pitch diameter against standards.

Applications depend on load, environment, and assembly requirements. Material choice, lubrication, and coatings influence wear and seizure risk. Compatibility between male and female threads, along with proper engagement length and aligned installation, are essential for reliable fastening. Standards from organizations such as ISO, ANSI/ASME, and DIN guide design, manufacturing, and inspection to ensure interchangeability across industries.