Stigma (letter) Stigma (letter) Stigma (ϛ) is a ligature of the Greek letters sigma (Σ) and tau (Τ), which was used in writing Greek between the Middle Ages and the 19th century. It is also used as a numeral symbol for the number 6. In this unrelated function, it is a continuation of the old letter digamma (originally Ϝ, cursive form ), which had served as a numeral since antiquity and was conflated with the σ-τ ligature in the minuscule handwriting of the Middle Ages. The στ ligature (, ) was one of many ligature forms that came into widespread use as
Torque multiplier example, a torque multiplier with a rating of 3:1 will turn its output shaft with three times the torque, but at one third the speed, of the input shaft. However, due to friction and other inefficiencies in the mechanism, the output torque is slightly lower than the theoretical output. Torque multipliers are most often used when a compressed air powered impact wrench is unavailable due to remote locations without power, or where cost considerations require manually operated tools which do not require any power supply or power source of any kind. There are many instances where screws, bolts and other