This Standard specifies the most important design and metrological characteristics of gage blocks with a rectangular or square cross-section and a nominal length ln ranging from 0.5mm to 1000mm for metric sizes and 0.0010in to 40in for inch sizes. It is not the intent of this Standard to preclude the use, by contractual agreement, of gage blocks of other shapes, grades or materials. Limit deviations and tolerances are stated for the calibration Grade K and for the Grades 00, 0 , AS-1, and AS-2 for various measuring purposes.