Linksgängige

Linksgängige is a German term that translates to "left-hand thread" or "left-handed thread" in English. It refers to a type of screw thread where the nut or bolt must be turned counter-clockwise to tighten it. This is the opposite of the more common right-hand thread, which tightens when turned clockwise.

The concept of left-hand threads is utilized in specific mechanical applications where it provides an advantage. One common use is in bicycles, particularly on the left pedal and the left crank arm. This design prevents the pedal from loosening due to the natural rotation of the wheel during pedaling. Similarly, some axle nuts, particularly on vehicles designed for specific regions or purposes, might employ left-hand threads to prevent loosening under operational stresses.

Another application can be found in certain threaded rods or bolts that are subjected to rotational forces that would otherwise tend to unscrew a standard right-hand thread. By using a left-hand thread, these components are effectively locked in place by the very forces that might loosen a conventional thread. The identification of a left-hand thread is typically through visual inspection or by attempting to tighten it; if it tightens counter-clockwise, it is a linksgängige thread.