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
Cap torque tester variations can modify product characteristics with a result of different torque measurement. Cap torque tester The cap torque tester is used in the packaging industry to measure the opening or closuring torque of the screwing cap. It is a piece of specific quality control equipment that can be placed on the production line or in the laboratory. A torque tester is required during the packaging design process. It can be used as a destructive tester to identify if there is any material weakness of the packaging during the screwing process. It also allows one to define the torque tolerances of