ISO

The direction of twist designation for yarns, complicated yarns, rovings, slivers, slubbings, cordage, and related items is standardized globally under ISO 2. The direction of twists is indicated by the capital letters S and Z in the standard, as indicated by the slanting direction of these two letters’ centres. The direction in which the twists move […]

ISO 1 is an international standard set by the International Organization for Standardization that specifies the standard reference temperature for geometrical product specification and verification. The temperature is fixed at 20 degrees Celsius (°C), which exactly equals both 293.15 kelvin (K) and 68 degrees Fahrenheit (°F). Due to thermal expansion, precision length measurements need to be made at